Mike Pence sworn in as Vice President as Donald Trump prepares for power

Mike Pence has taken the oath of office to become Vice President, as Donald Trump prepares to become the 45th President of the United States.

President-elect Trump gave a thumbs-up, pumped his fist and mouthed "thank you" as he walked to his seat at the US Capitol in Washington DC for the inauguration ceremony.

President Barack Obama and Mr Trump greeted well wishers as they arrived, following a final meeting between the pair at the White House.

:: LIVE: Trump's inauguration day

Dignitaries and VIPs also gathered, including Mr Trump's opponent in November's election, Hillary Clinton.

Mr Trump is expected to take the oath of office shortly after 5pm UK time. He will then give his inaugural address, which is expected to last 20 minutes.

Mr Trump and Mr Obama earlier travelled the 2.5 miles down Pennsylvania Avenue from the White House, along with Vice President Joe Biden, First Lady Michelle Obama and Mr Trump's wife Melania.

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Mr Obama and Michelle greeted Mr Trump and Mrs Trump on the steps of the grand North Portico, the column-lined entrance to the White House facing Pennsylvania Avenue.

The outgoing President told his successor it was good to see him, while Mrs Trump brought a gift for the soon to be former first lady.

Mrs Trump initially reached out to shake Mrs Obama's hand, but Mrs Obama instead gave her a hug.

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There has been violence on the streets of Washington before the ceremony, with black-clad protesters smashing car and shop windows and throwing stones.

Mr Trump begun his inauguration day with a visit to a church in Washington, and emerged from Blair House, a government guest house next to the White House, with Melania just after 1.30pm UK time.

They then took a motorcade for the short journey to St John's Episcopal Church, where they were also joined by Mr Trump's adult children.

Before emerging for the church service, Mr Trump wrote on Twitter: "It all begins today! I will see you at 11:00 A.M. for the swearing-in. THE MOVEMENT CONTINUES - THE WORK BEGINS!"

Mr Obama has also been tweeting on his final day in office, saying: "It's been the honor of my life to serve you. You made me a better leader and a better man."

He added: "I won't stop; I'll be right there with you as a citizen, inspired by your voices of truth and justice, good humor, and love."

Mr Trump's inaugural address is expected to last for around 20 minutes.

His spokesman Sean Spicer said the speech would be "less of an agenda and more of a philosophical document".

However, dozens of Democratic members of the House of Representatives have said they will boycott the inauguration, amid allegations that Democratic Party computers were hacked by Russians in the weeks before the election.

Mr Trump is expected to sign a raft of Executive Orders overturning Mr Obama's policies soon after assuming power - and make an early start on key pledges on immigration, including the building of a new wall or fence on the Mexican border.

Security for the inauguration is likely to cost around $100m (£81m), with 28,000 uniformed personnel working under the direction of the US Secret Service.

Up to a million spectators are expected to watch the day's events, including a parade in which the new President traditionally walks at least part of the route back to the White House.

Supporters of Mr Trump started lining up at security checkpoints before dawn to take their places on the National Mall. Protesters were also out early, some wearing orange jumpsuits with black hoods over their faces.

Three days of inaugural events kicked off on Thursday, when Mr Trump flew to Washington in a government plane, saluting an Air Force officer as he descended the steps with his wife.

He and the incoming Vice President, Mike Pence, laid a wreath at Arlington National Cemetery before joining supporters for an evening concert at the Lincoln Memorial.

More follows...

Read more:

:: Obama era - Sky News specialists give their verdict
:: What will Trump's impact on the world be?
:: How Trump ripped up the foreign policy playbook
:: Your guide to Trump's inauguration

:: Watch continuing live coverage of the inauguration on Sky News and Sky Atlantic.

Adam Boulton is in the US, and will present a special Sky News programme - Trump: America's President - at midnight tonight.