DONALD Trump has promised to be "president for all Americans" after pulling off an astonishing victory in a race for the White House which has exposed deep rifts within the United States.
President Barack Obama has said he is heartened by the president elect's call for unity after his victory adding "we are now all rooting for his success in uniting and leading the country".
Mr Obama spoke to reporters in the Rose Garden of the White House in a post-election ritual meant to signal the peaceful transition of power from one president to the next.
He vowed to do all he could to ensure a smooth transition and tried to buck up Democrats still reeling with disappointment and shock.
In the aftermath of a bitter campaign Mr Trump sought to unite the country behind his leadership and promised to renew the American dream.
Against almost all pollsters' predictions, the Republican candidate easily cleared the hurdle of 270 US electoral college votes needed to secure victory, though Democrat rival Hillary Clinton looks set to have achieved a higher tally of actual votes than Mr Trump.
Despite losing Tuesday's presidential election, Hillary Clinton appears to be on pace to win the popular vote
The result would be an ironic twist in an election in which her opponent repeatedly said the system was rigged against him.
Just two days before Election Day, Republican businessman Donald Trump tweeted: "The Electoral College is a disaster for a democracy."
As it turns out, without the Electoral College, President-elect Trump probably would not be heading for the White House.
A day after Election Day, Ms Clinton held a narrow lead in the popular vote, according to unofficial results.
With nearly 125 million votes counted, Ms Clinton had 47.7 per cent of the vote and President-elect Trump had 47.5 per cent. That is a lead of about 236,000 votes.
Many states count votes after Election Day, so Ms Clinton is not guaranteed to keep her lead.
Earlier, in an upbeat and conciliatory message in stark contrast to the vicious battle for the presidency, Mr Trump said: "No dream is too big, no challenge is too great. Nothing we want for our future is beyond our reach.
"America will no longer settle for anything less than the best."
Mrs Clinton called on supporters to accept the outcome of the election and ensure a smooth and peaceful handover of power from Barack Obama. Flanked by husband Bill and daughter Chelsea in New York, she vowed to continue to defend equal rights and the rule of law.
The former first lady said the election race had revealed that "our nation is more deeply divided than we thought", but said she hoped that Mr Trump would be "a successful president for all Americans".
"We must accept this result and then look to the future," said Mrs Clinton. "Donald Trump is going to be our president. We owe him an open mind and the chance to lead."
The billionaire businessman will take over as 45th president of the United States in January, after voters gambled on his pledge to "make America great again".
Speaking at a victory party in New York after Mrs Clinton conceded defeat, Mr Trump urged Americans to put the election behind them.
"It is time for us to come together as one united people," he said.
"I pledge to every citizen of our land that I will be president for all Americans."
Taking to the stage with his family, including wife Melania, Mr Trump promised a plan to double economic growth and invest in world-class infrastructure.
"Working together, we will begin the urgent task of rebuilding our nation and renewing the American dream."
It would be a "beautiful thing", he said.
Prime Minister Theresa May wrote to Mr Trump to congratulate him on his victory, declaring that Britain and America will remain "strong and close partners".
But his victory sparked horror in some quarters of British politics, with Liberal Democrat leader Tim Farron lamenting that liberal values had been "defeated" in the US, while Scottish First Minister Nicola Sturgeon said the outcome would be greeted with "a real sense of anxiety" around the world.
Labour leader Jeremy Corbyn said Mr Trump's victory was "an unmistakable rejection of a political establishment and an economic system that simply isn't working for most people", but warned the answers he is offering to America's problems are "clearly wrong".
German chancellor Angela Merkel pointedly offered the president-elect "close co-operation" on the basis of the shared values of "democracy, freedom, respect for the law and for the dignity of human beings, independent of origin, skin colour, religion, gender, sexual orientation or political views".
Russian president Vladimir Putin sent Mr Trump a telegram of congratulations, expressing "his hope to work together for removing Russian-American relations from their crisis state".
The election of the outspoken businessman and TV personality, who has never held public office, shows the anger and frustration of many Americans who felt left behind by the economy and ignored by the political establishment.
Mr Trump said: "The forgotten men and women of our country will be forgotten no longer."
The Republican candidate sealed victory when he took key battleground states Pennsylvania and Wisconsin.
The Clinton camp initially refused to throw in the towel, but Mr Trump told supporters shortly before 8am UK time: "I've just received a call from secretary Clinton. She congratulated us - it's about us - on our victory and I congratulated her and her family on a very, very hard-fought campaign."
During the battle for the Oval Office, Mr Trump had repeatedly described his rival as "crooked Hillary" and called her a "nasty woman".
But he struck a conciliatory tone in his first appearance as president-elect, thanking the former secretary of state for her "service" to the country.
Mr Trump sought to give reassurance to international leaders about his intentions: "I want to tell the world community that, while we will always put America's interests first, we will deal fairly with everyone - all people and all other nations.
"We will seek common ground not hostility, partnership not conflict."
US markets proved resilient in the face of the surprise of the result, defying expectations of a slump. The Dow Jones Industrial Average and the S&P 500 indexes were up 0.3 per cent and 0.2 per cent respectively.
Initial panic in London, which saw falls of up to 2 per cent when the market opened, was quickly reversed, with the FTSE 100 recovering to rise 0.85 per cent by the close of the day.
But share values tumbled in Asia and the dollar and Mexican peso both fell.
Mr Trump teased supporters with the prospect of potentially serving the maximum, two full terms as president.
He said that "at the end of two years, or three years, or four years - or maybe even eight years - you will say that so many of you worked so hard, but you will say that was something that you were really very proud to do".
