WASHINGTON - Mr Donald Trump took office as the 45th president of the United States on Friday US time (Saturday Jan 21, Singapore time), promising that it would be "America first" from now on.
"From this day forward, a new vision will govern our land. From this day forward, it's going to be only America first," Mr Trump said in his first speech as the US president. "Every decision on trade, on taxes, on immigration, on foreign affairs, will be made to benefit American workers and American factories," he said.
At the inauguration ceremony, Mr Trump was administered the oath by Chief Justice John Roberts. With his wife Melania by his side, Mr Trump took the oath using two Bibles - one from President Abraham Lincoln's inauguration in 1861 and the other was given to him by his mother when he was nine years old.
Mr Mike Pence, 57, was also sworn in as vice-president at the ceremony by Supreme Court associate justice Clarence Thomas.
Among the guests were Mr Trump's defeated election opponent Hillary Clinton, as well as former presidents Barack Obama, Bill Clinton, Jimmy Carter and George W. Bush.
After the ceremony, Mr Obama and his wife Michelle departed the Capitol, turning a page on eight years of Democratic leadership in the White House.
'THE WORK BEGINS'
In his first tweet early Friday morning, Mr Trump wrote: "It all begins today! I will see you at 11am for the swearing-in. THE MOVEMENT CONTINUES - THE WORK BEGINS!"
He and his family attended a service at St. John's Church, before heading to the White House for the last meeting with Mr Obama.
Mr Obama and First Lady Michelle greeted Mr Trump and his wife Melania on the steps of the White House, before heading into the building for tea and coffee. Mr Obama could be heard saying: "Mr President elect! How are you? Congratulations."
PROTESTS AGAINST MR TRUMP
Before the inauguration, some anti-Trump activists, clad in black, took to the streets, smashing store and car windows, and fighting with police who responded with pepper spray and stun grenades.
About 500 people marched through the downtown area, breaking the windows of a Bank of America branch, a McDonald's outlet and a Starbucks outlet.
Liberal activists also scuffled with police after attempting to block Mr Trump's supporters streaming in for the ceremony. Protesters linked arms at one of the security checkpoints leading to the public viewing area, and several were led away by police in riot helmets and body armour.
The night before the inauguration, protesters tried to disrupt a party organised by a so-called "alt-right" white nationalist group in the National Press Club building. Police used smoke bombs and made several arrests.
In New York, a bevy of celebrities and the city's mayor, Mr Bill de Blasio, led a protest against Mr Trump outside his hotel in Manhattan. Protests also broke out in several other cities, and more are scheduled over the weekend.
FIRST TASKS AS PRESIDENT
Mr Trump is expected to sign orders very soon after the inauguration - to dismantle his predecessor Obama's Affordable Care Act or Obamacare, deport illegal immigrants, start work on a wall on the Mexican border; renegotiate the North Atlantic Free Trade Agreement (Nafta) and opt out of the Trans Pacific Partnership (TPP).
Mr Trump, born in the then-industrial district of Queens in New York City, parleyed his way to prime property in Manhattan, became a reality TV star, and built a global business empire.
And last year, connecting with the public mood in conservative post-industrial middle class rural America, the political outsider controversially won his way through the Republican Party ranks on a passionately nationalist platform, grabbing an election win that stunned the Washington political establishment.
Mr Trump has promised to shake up that establishment. White House Press Secretary Sean Spicer told reporters on Jan 19. "It's going to be robust, not just day one, but I think first week, first month, probably first term."
His agenda includes slashing the bureaucracy, lifting federal regulations on industry, lowering taxes, getting tough on trade terms with China and Mexico, and resetting the long-tense relationship with Russia.
Many of these will be radical changes to the status quo, in the name of his campaign slogan "Make America Great Again" and his pledge to create millions of jobs.
Most of his Cabinet picks have not yet passed their Senate confirmation hearings though, and up to 4,000 other positions in the new administration have yet to be appointed.
Mr Trump's Cabinet is dominated by millionaires, billionaires and retired generals.
"We have by far the highest IQ of any Cabinet ever assembled" he said at an inauguration-eve party for donors in the capital.