Donald Trump is about to be sworn in as the 45th president of the United States, taking power over a divided country after winning a savage campaign and setting the country on a new, uncertain path at home and abroad.
In a ceremony likely to be attended by 900,000 people, including protesters, Mr Trump and his vice-president, Mike Pence, will take the oath of office at midday on Friday (6am Saturday NZT) outside the domed US Capitol in Washington DC, with US Chief Justice John Roberts presiding.
Follow live online coverage here.
Mr Trump, 70, enters the White House with work to do to bolster his image. During a testy transition period since his stunning November election win, the wealthy New York businessman and former reality TV star has repeatedly engaged in Twitter attacks against his critics, so much so that fellow Republican Senator John McCain told CNN that Mr Trump seemed to want to "engage with every windmill that he can find".
At a concert on the eve of his inauguration, the president-elect addressed a crowd of cheering supporters and promised to bring change.
"We're going to unify our country," Mr Trump said, speaking on the steps of the Lincoln Memorial.
"We're going to make America great for all of our people. Everybody, everybody, throughout all of our country. That includes the inner cities."
His supporters have been streaming into Washington DC, and he reminded them that many had doubted the campaign's chances of success.
"They forgot about a lot of us," he said. "On the campaign, I called it the forgotten man and the forgotten woman. Well, you're not forgotten anymore."
An ABC News/Washington Post poll this week found only 40 percent of Americans viewed Mr Trump favourably, the lowest rating for an incoming president since Democrat Jimmy Carter in 1977, and the same percentage approved of how he has handled the transition.
His ascendancy to the White House, while welcomed by Republicans tired of Democrat Barack Obama's eight years, raises a host of questions for the United States at home and abroad.
He campaigned on a pledge to take the country on a more isolationist, protectionist "America First" path and has vowed to impose a 35 percent tariff on goods exported to the United States by US companies that went abroad.
Mr Trump's desire for warmer ties with Russian President Vladimir Putin and threats to cut funding for NATO nations has American allies from Britain to the Baltics worried that the traditional US security umbrella will be diminished.
The president-elect's critics also point to the conclusion of US intelligence agencies that Russia used hacking and other methods during the campaign to try to tilt the election in Mr Trump's favour.
Mr Trump has acknowledged the finding - denied by Moscow - that Russia was behind the hacking but said it did not affect the outcome of the election.
In the Middle East, Mr Trump has said he wants to move the US embassy in Israel from Tel Aviv to Jerusalem, at the risk of angering Arabs. He has yet to sketch out how he plans to carry out a campaign pledge to "knock the hell out of" Islamic State militants.
The inaugural festivities might have a more partisan edge than usual given Mr Trump's scorching campaign, and continuing confrontations between him and his Democratic critics over the new president's pledge to roll back many of Mr Obama's policies and his take-no-prisoners Twitter attacks.
More than 50 Democratic lawmakers plan to stay away from the proceedings to protest Mr Trump, spurred on after he derided US Representative John Lewis of Georgia, a hero of the civil rights movement, for calling Mr Trump an illegitimate president.
Thousands of anti-Trump protesters were expected among an inauguration crowd that organisers estimated will be upwards of 900,000.
Many protesters will be spilling into the streets of Washington on Saturday when a "Women's March on Washington" is planned. Protests are also planned in cities abroad.
Mr Trump will launch his presidency with an inaugural address that will last about 20 minutes and that he has been writing himself with the help of top aides. It will be "a very personal and sincere statement about his vision for the country", his spokesman Sean Spicer said.
"He'll talk about infrastructure and education, our manufacturing base. I think it's going to be less of an agenda and more of a philosophical document - a vision of where he sees the country, the proper role of government, the role of citizens," Mr Spicer told reporters.
- Reuters / BBC