Trump approaches 100-day milestone, but what progress has he made on his agenda?
"When we win on November 8 and elect a Republican Congress, we will be able to immediately repeal and replace Obamacare. We have to do it," Mr Trump told supporters one week out from election day.
When Republicans seized control of both chambers of Congress, as well as the White House, they finally had their mandate to repeal Barack Obama's signature policy.
What they didn't have was consensus. How much of the act they planned to repeal, and what exactly they intended to replace it with, was the source of constant friction within the party.
In many red states the expansion of Medicaid had proven life-saving. It had, as intended, provided millions of people with access to affordable health care and Republican governors travelled to Washington to lobby their federal colleagues not to make changes that would see their constituents suffer.
The House Freedom Caucus — a group of ultra-conservative and libertarian Republicans — didn't just want to repeal and replace Obamacare. They wanted government-sponsored health care gone for good.
Knowing no Democrats would be swayed, if the Freedom Caucus voted against the legislation proposed by Speaker Paul Ryan, which they argued was "Obamacare lite", the bill would fail.
An incensed President gave the Freedom Caucus an ultimatum. If they didn't support what was on offer, he would abandon repealing Obamacare altogether. But they called Mr Trump's bluff.
On the day the legislation was set to be voted on, Speaker Paul Ryan pulled the bill, unable to secure the required votes.
Undeterred by this humbling defeat, Mr Trump indicated a willingness to continue working on health care, and was even open to negotiating with Democrats to come up with a passable plan, but made no apology for his inability to close the deal.
"I guess I'm here what, 64 days? I never said repeal and replace Obamacare — you've all heard my speeches — I never said repeal it and replace it within 64 days."
- by Brooke Wylie, ABC News producer in Washington DC
The Supreme Court
A bitter partisan battle has raged in Washington since conservative Justice Antonin Scalia died more than a year ago, leaving a vacant Supreme Court seat.
The nine justices sit on the court for life, and have the power to interpret the constitution in ways which have fundamentally influenced American society for generations.
Democrats argued the seat should have been filled by the Obama administration, which still had 11 months to govern when Justice Scalia died.
But Senate Majority Leader Mitch McConnell refused to even meet with Mr Obama's nominee Merrick Garland, who would have been the third Obama-appointed Supreme Court justice.
He was widely considered to be a moderate and respected choice by both sides of the aisle, and Mr McConnell's refusal to set hearings for him enraged Democrats.
In the lead-up to election day, Mr Trump had campaigned extensively on replacing a conservative with a conservative, and Neil Gorsuch was on the shortlist of potential replacements being considered.
After an embarrassing defeat on repealing Obamacare, the stakes were high for Republicans to ensure Mr Trump delivered on his commitment.
Senator McConnell's gamble paid off. On Day 81 of his new administration, Mr Trump and the Republicans landed a key victory with the swearing-in of Mr Gorsuch as the 113th justice of the Supreme Court.
With the appointment of Justice Gorsuch, the ideological majority on the court once again leans conservative (5-4). But this victory, among the first of the new administration, wasn't without a price.
His nomination was opposed by most Senate Democrats, who blocked the confirmation with a filibuster, prompting Senator McConnell to follow through on a long-promised threat to change Senate rules by lowering the minimum vote threshold for progressing Supreme Court nominees from 60 to a simple majority.
While the move referred to on Capitol Hill as "the nuclear option" will benefit Republicans in the short term, it greatly reduces the minority party's negotiating power in the Senate, where members have traditionally been encouraged to deliberate thoughtfully on legislation rather than vote strictly along party lines.
- by Brooke Wylie, ABC News producer in Washington DC
Mr Trump campaigned on a promise that he'd lead America out of $19 trillion debt. As a billionaire businessman, he argued that only he could do it.
He also promised to eliminate the federal debt and get the world's largest economy working again.
How? Through tax reform and performing deep cuts on most federal government departments.
Since taking office, Mr Trump has moved to wipe out billions of dollars worth of government spending.
The Environmental Protection Agency (31 per cent of funding) and the State Department (29 per cent) will experience the biggest shavings, according to the budget proposal released last month.
These plans mean programs combating climate change will be eliminated and funding for UN peacekeeping and organisations like the World Bank will be slashed.
Another penny-pinching plan was to repeal and replace the Affordable Health Care Act, which failed in Congress and has been postponed temporarily.
Many of those anticipated savings will be used to help offset increased spending in three areas: the Department of Veterans Affairs, Homeland Security and the military.
Mr Trump's budget proposal is just that — a proposal. In 2016, Mr Obama's preliminary budget was disregarded by Congress altogether.
Balancing the books for America will also prove tough as the Trump administration looks at providing tax cuts. Mr Trump has proposed reducing the number of tax brackets from seven to three and slashing the corporate tax rate from 35 per cent to 15 per cent.
The Tax Policy Centre says that would result in federal revenue falling by $US6.2 trillion over the next 10 years and the top 1 per cent of income earners will receive 47 per cent of those savings.
House Republicans proposed their own tax reform plan in 2016 and likewise are looking to make savings in the trillions of dollars.
Tax reform is the new priority for Mr Trump but he'll need the help of Capitol Hill for it to pass. Whether he's learnt from the failed repeal and replace of Obamacare remains to be seen.
As for eliminating the debt in the next four years? Well, Mr Trump's budget director Mick Mulvaney dismissed that pledge as "hyperbole".
- by Roscoe Whalan, ABC News producer in Washington DC
The Russia connection
There are now three separate enquiries underway into Russian interference in the presidential election, being run by the FBI, the House and the Senate.
The enquiries are looking at Russian efforts to undermine the campaign (and US democracy) through involvement with WikiLeaks, perpetrating Democratic Party email hacks and propagating fake news to influence voters in swing states.
They're further examining direct links between the Trump campaign and Russia.
In the end the key question is this: did Russia attempt to influence the outcome of the US presidential election to undermine Hillary Clinton and to get Donald Trump elected? The secondary question is: did the Trump campaign participate in this either willingly or unwittingly?
The Trump administration has repeatedly denied collusion with Russia, saying it's fake news being spread by the media and Democratic Party to undermine the credibility of the administration.
However, it's true to say that former Trump campaign manager Paul Manafort had past ties with Russia, as did policy adviser Carter Page.
Trump confidant Roger Stone admits he spoke with the Russian intelligence-linked Guccifer 2.0 who hacked the Democratic National Committee and former National Security Adviser Mike Flynn was sacked after misleading Congress about the content of his conversations with the Russian Ambassador.
Attorney-General Jeff Sessions, then a foreign policy adviser to Mr Trump, also met repeatedly with the ambassador during the campaign.
The fact that the FBI has confirmed it's investigating Russia ties is highly significant, but FBI counter-intelligence investigations frequently take years and often yield little.
While the Senate continues to promise a bipartisan investigation, the House probe has descended into farce after its chairman was forced to step down, at least temporarily, after viewing documents provided by White House staff and then briefing the president on the matter.
Meanwhile in further evidence that the focus is on politics rather than finding the truth, the Obama administration has been accused of leaking intelligence.
There's growing concern that the extent of Russian involvement will never be fully exposed, meaning a cloud of suspicion over the Trump administration may never lift and the US political system may have sustained permanent damage.
More to the point, there's the question of whether enemy efforts to influence elections the world over are part of the 'new normal' where spies and their collaborators operate with impunity.
It's worth noting that since the US launched torpedoes at Syria over the use of chemical weapons, causing a stoush with Russia, discussion about the Trump campaign's relationship with the Kremlin has all but evaporated.
- by Zoe Daniel, ABC News US bureau chief
The travel ban
Whatever happened to Mr Trump's travel bans on people from six Muslim majority countries?
They're stuck in the courts, which means the bans can't be enforced.
After the first Executive Order affecting people from seven nations stalled due to mass protests and legal action in late January, the text was withdrawn and rewritten.
Iraq was taken off the list due to the close relationship between the two countries and efforts made by the Iraqi government to implement effective security measures.
Under the revamped order citizens of six countries remained banned for 90 days, including Syria, Iran, Libya, Somalia, Sudan and Yemen. Entry of all refugees was banned for 120 days, toning down the original order's plan to ban Syrian refugees indefinitely.
But again, the courts stepped in.
The ban was due to take effect on March 16 but a judge in Hawaii issued a restraining order to apply nationwide. That order has since been extended and remains in place.
A second judge, in Maryland, also issued an order specifically blocking the 90-day ban on people from the named countries.
Both judges cited then candidate Trump's comments in relation to banning Muslims during his campaign as part of their rulings.
More than 150 tech companies, including Google, Facebook, Tesla and Uber have since joined forces to file a legal brief against the order, citing potential disadvantage if they can't attract skilled employees from abroad.
Emirates Airlines has announced plans to reduce flights to the US, blaming reduced demand due to the bans.
A federal appeals court has announced plans to hear arguments on the Maryland case in May. The Justice Department had indicated it would ask for an earlier hearing due to national security concerns.
The administration has not appealed the Hawaii ruling. If it did so the appeal would be heard by the 9th Circuit Court of Appeals in San Francisco, the same court that refused to overturn a lower judge's injunction on the first set of travel bans.
The President has previously indicated that he would take the issue all the way to the Supreme Court, if necessary.
- by Zoe Daniel, ABC News US bureau chief
Mr Trump has famously — and now he has responsibility for setting climate policies of the world's second biggest emitter.
The US President has backed away from the Chinese hoax theory but has made it clear climate change will not be a priority.
When his draft budget was released the biggest target was the Environmental Protection Agency, which lost almost a third of its funding.
Other agencies are facing sweeping cuts to any programs involving climate change, but some will continue as long as they are renamed.
"Regarding the question as to climate change, I think the president was fairly straightforward: we're not spending money on that any more," said his budget director Mick Mulvaney
The President's advisers are now meeting to decide whether to recommend the US withdraw from the Paris Climate Accord.
The US pledged to reduce its emissions by 26-28 per cent of 2005 levels by 2028.
Mr Trump has previously said the US will withdraw but has been largely silent on the issue since taking office and his course is not yet clear.
During his confirmation hearings Mr Trump's Secretary of State Rex Tillerson said the US would be better served by remaining at the table rather than withdrawing.
Withdrawing from the agreement would not lead to its collapse but could strain relationships and make it difficult for US companies eager for a slice of the growing renewables market.
At the end of the month a major climate march is planned for DC and cities around the United States to protest the president's climate policies.
Protesters have also been upset by the president's executive orders reviving the Keystone and North Dakota pipelines, which Mr Trump says will create many new jobs.
- by Conor Duffy, ABC News North America correspondent
Rebooting the economy
Mr Trump promised to overhaul free-trade deals, cut regulations on business and punish companies who move their operations overseas, in an effort to protect American jobs.
In his first 100 days, he has taken some steps towards those goals but mostly through executive orders, which will take some time to create change.
On his first day in office he pulled out of the Trans-Pacific Partnership — a deal that took years to negotiate — calling it a "disaster".
During his campaign he threatened to scrap the North American Free Trade Agreement (NAFTA) with Canada and Mexico. So far, he has written a letter to Congress asking for some small tweaks and just this week said he would announce more plans "some time over the next two weeks".
He promised to restore confidence to the energy and manufacturing sectors by abolishing environmental regulations enacted by the Obama administration.
He has dismantled some of them, and there has been an uptick in coal mining activity and investment since he was elected.
The President has signed orders supporting two controversial oil pipelines — Keystone XL and Dakota Access — both of which had stalled under Mr Obama. Both projects could still face legal challenges.
At the same time he signed an order to expedite environmental reviews of other infrastructure projects. The US State Department determined in 2015 the Keystone project would create 42,000 jobs over two years of construction, reducing to 50 once built.
This week Mr Trump released a tax plan that proposes slashing the rate on corporate and pass-through business profits to 15 per cent from 35 per cent or more, while also offering tax cuts to average Americans.
However, under US law, only Congress can make major tax law changes and Mr Trump's plan is really just a starting point for further discussion.
In trying to make sure Americans are not losing jobs to foreigners, Mr Trump has ordered a review of America's H1B temporary worker visa program.
Each year 85,000 H1B visas are issued and they are widely used in the tech industry. Critics say curbing the program could drive companies off shore.
Mr Trump's promise to fine companies who relocate to other countries remains unfulfilled.
At times he has turned to Twitter to hector businesses about their operations and has claimed credit for companies — including Lockheed Martin, GM and Ford — keeping or expanding operations in America.
Since his election he has held events at a number of businesses across the country to talk about jobs. He visited Boeing in South Carolina, Carrier air-conditioning in Indiana and Snap-On tool manufacturing in Wisconsin. A visit to a Harley Davidson factory in Milwaukee was cancelled because of fears around protests.
Mr Trump staked his presidency on fighting for the working men and women of America but now in office he also has to work with foreign governments, which may be why he has ended up taking a softer line on NAFTA and dumped his promise to label China a currency manipulator.
Some of the protectionist initiatives that may eventuate from his flurry of executive orders could still result in testing relations with allies and trading partners.
The next big item on his economic agenda to look out for will be the release of his tax reform plan.
- by Stephanie March, ABC News North America correspondent
Perhaps Mr Trump's most infamous catchphrase during the election campaign was that he'd "build a wall" on the southern border between the United States and Mexico.
The second key component of that plan was that Mexico would pay.
Within his first week in office, he signed an executive order on "Border Security" marking the first step in building a full-length border. He signed another order to eliminate funding for sanctuary cities, which offer safe harbour for undocumented migrants.
That order has since been blocked by a judge in San Francisco.
Mr Trump promised a "physical, tall, powerful, beautiful southern border wall", which the administration has said will cost $US21 billion.
The US will pay for the wall initially though Mr Trump insists the money will eventually be recouped from Mexico.
Contractors have been asked to submit plans for the barrier, which Mr Trump expects to cover 1,000 miles.
His determination to be tough on the border, build a wall — and make Mexico pay for it — saw a visit from Mexico's President Pena Nieto cancelled and former president Vincente Fox continue his .
Mr Trump has also announced plans to hire an extra 15,000 customs and immigration officers to reduce the estimated 11 million undocumented immigrants living in the United States.
Anecdotal reports suggest the rhetoric alone is having an impact, with arrivals from Mexico said to be slowing.
Just this week, it was revealed that the first "DREAMer" (a person granted deportation protection under the Deferred Action for Childhood Arrivals — DACA — program created by Mr Obama) had been deported back to Mexico.
However, Mr Trump has said that DREAMers should "rest easy" and that the administration is only after criminals.
Homeland Security Secretary John Kelly said construction of the wall should begin by the end of the American summer.
- by Conor Duffy, ABC News North America correspondent
Since taking office, Mr Trump has reversed his stance on at least one major position he held on US relations with China, and has struck a markedly different tone on several others.
During his Gettysburg address as a candidate in October, Mr Trump vowed to label China a currency manipulator within his first 100 days in office.
During his campaign, he also described China as "the world champions" of currency manipulation, and "the greatest currency manipulators ever".
The accusation is that China fixes the value of the yuan against other currencies at an artificially low rate, to help its exports compete.
But in April this year, Mr Trump told the Wall Street Journal "they're not currency manipulators".
The first Treasury Department currency report under his presidency also didn't name China, nor any other country, as a manipulator.
Mr Trump explained his shift, saying China hadn't manipulated its currency "for months", and on Twitter he added: "Why would I call China a currency manipulator when they are working with us on the North Korean problem?"
Mr Trump as a candidate also threatened to impose tariffs of up to 45 per cent on Chinese imports if Beijing failed to take measures to address the trade imbalance between the two countries.
At one point he said China was "raping our country", in reference to its trade practices.
This is a theme he has continued to emphasise (albeit in more diplomatic terms) after taking office, including through his pick of long-time China critic Peter Navarro to head a trade advisory council.
So far the pressure appears to have convinced Beijing that there is room for negotiation on the issue, with China's government constantly warning that a trade war would be detrimental for all.
During the first summit with Chinese President Xi Jinping, Mr Trump agreed to a 100-day plan for trade talks between the two countries.
So far, there have been no moves on Mr Trump's part to start the process of legislating for new tariffs.
He has stated an overall goal of reducing the trade deficit with China, which stood at $US347 billion in 2016.
It's worth noting that the deficit peaked at $US367 billion in 2015, hence if there is a further reduction, it can be seen to have begun during the final year of the Obama administration.
Taiwan phone call
Mr Trump's candidacy heavily focussed on trade rather than strategic policy in Asia, but during his transition period as president-elect in December, he took a phone call from Taiwan's leader Tsai Ing-wen, breaking an almost four-decades-old protocol for the US to avoid official contacts with the self-ruled island's government.
In a media interview, Mr Trump questioned why the US should be bound to the One China policy unless it makes a deal with China on "other things, including trade".
In February, he agreed to honour the One China policy at the request of Mr Xi.
Publicly, neither government linked Mr Trump's reversal to any deal.
Finally on strategic matters, Mr Trump insisted during the campaign that China holds huge influence over North Korea, and as president, he's been using both coercive and friendly rhetoric towards Mr Xi to help deal with Pyongyang's missile and nuclear program.
China appears to be applying more economic pressure as a result, seemingly enforcing a UN resolution that limits the amount of coal it can import from North Korea.
On another contentious issue — China's military base islands built in defiance of international law in the South China Sea — Mr Trump has hardly raised the issue publicly.
Prior to his swearing in, his Secretary of State nominee Rex Tillerson said in January that China should be "denied access" to the islands it constructed.
But in another reversal, Mr Trump's Defence Secretary Jim Mattis in February said "we do not see any need for dramatic military moves" in the South China Sea.
In China's state-controlled media, the series of reversals and policy shifts are being reported as weaknesses, with a view forming in Beijing that the US President has a penchant for bluffing.
- By Bill Birtles, China correspondent