Donald Trump arrived at the White House in Washington this morning as he prepared to take the oath of office and become the 45th president of the United States.

Trump and his wife, Melania, were greeted by President Barack Obama and First Lady Michelle Obama on a red carpet at the north portico of the White House.

The couples were having tea and coffee together before travelling to Capitol Hill for the transfer of power.

"It all begins today! ... THE MOVEMENT CONTINUES - THE WORK BEGINS!" Trump declared earlier on Twitter, ahead of the day's festivities.

Crowds of Trump supporters along with protesters were arriving on the National Mall as a light drizzle began to fall. Many were wearing red 'Make America Great Again' caps and expressed excitement about what they view as a new era in US politics focused on job creation and other pocketbook issues.

"I absolutely love the man," Sandra Edwards, 46, a nurse from southern Virginia told dpa. "I'm really excited he shares my desire to create jobs and being industries back."

VIPs, including former president George W Bush, were arriving at the Capitol for the festivities. Bush told reporters that his father, ailing former president George HW Bush, was doing better after being hospitalised earlier this week.

Trump will take oath at noon in the US

At noon (1am in Malaysia), Trump will place his hand on a Bible once used by Abraham Lincoln to take the presidential oath of office and begin the difficult task of leading a country sharply divided by his election.

The president-elect began the day with a traditional private worship service at St John's Church near the White House.

Obama left the Oval Office for the final time, giving a final "thank you" to the American people.

Just 40 percent of Americans view Trump favourably, the lowest of any recent president, pollster Gallup said, pointing to a 78 percent favourability rating for Obama in 2009.

As he prepares to take the reins from Obama, Trump has continued to blast his critics and dismiss the media even as he also seeks to deliver a message of job creation and focus on his campaign pledge to 'Make America Great Again'.

His inauguration festivities are designed with unity in mind and are to be accessible to the working class Americans who formed the backbone of his support.

But millions of Americans worry about the direction the United States will take under Trump amid vows to repeal Obama's signature healthcare law, pledges to build a wall along the US-Mexican border and the questioning of longstanding pillars of US foreign policy.

- dpa