Senator Roy Blunt joins Klobuchar - his inaugural co-chair - in hailing the ceremony going forward in spite of a pandemic and security threats.

He says every inaugural is - in the words of Ronald Reagan - is both "commonplace and miraculous", but its goal of a "determined democracy forging a more perfect union" is even more resonant today.

"The United States can only set an example to others if we are always working to be better than we have been", he said.

In a nod to the riot on 6 January, he said it had shown democracy was "fragile yet resilient".

"This is not a moment of division. It's a moment of unification."

Mark Savage
Music reporter, BBC News

Pop star Lady Gaga will sing the National Anthem shortly, following in the footsteps of Beyoncé and opera great Marian Anderson, who performed for both John F Kennedy and his predecessor Dwight D Eisenhower.

The singer, who campaigned for Joe Biden during the election, said she was "deeply honoured" to be chosen for the ceremony.

She spent Tuesday rehearsing for the performance, and posing for photos with the National Guard, who have been called in to protect the Capitol against security threats.

Image source, Reuters

Another senator, Roy Blunt, has taken to the stage now.

Meanwhile, it's noticeable that a number of high-profile figures, including Vice-President-elect Kamala Harris, have chosen to wear purple today.

The colour is traditionally seen in the US as a symbol of bipartisanship - a combination of the blue and red of the Democratic and Republican parties.

The gesture echoes calls for cooperation surrounding the inauguration and the theme of the ceremony, which itself is "America United".

Image source, Reuters

Image source, EPA

Image source, EPA

Image source, Getty Images

Minnesota Senator Amy Klobuchar, who ran against both Biden and Harris during the Democratic primary, is welcoming the new administration.

She also greets "a whole bunch of Bidens," in a reference to the large Biden family that are there today.

"This conveyance of this sacred trust between the leaders and its people takes place in front of this shining capitol dome for a reason," she says, adding that it is a sign that the US "union will go on".

Senator Amy Klobuchar is starting proceedings.

Nick Bryant
BBC New York Correspondent

Ever since Ronald Reagan became the first to be inaugurated on the west front of the Capitol, incoming presidents have peered out over National Mall crowded with supporters.

Joe Biden will see a carpet of flags.

The inaugural stands, rather than being crowded with lawmakers, family and friends, and officials in the new administration are sparsely populated because of social distancing protocols.

The Biden team is determined that this won’t be a super-spreader event.

Image source, Reuters

Joe Biden and his wife Jill have just arrived on the inaugural platform, after walking through the halls of Congress.

He is moments away from being sworn in as the 46th US president.

Image source, Sellers

A'Kayla is a young black woman from South Carolina and a college student who sees the incoming Biden/Harris administration as "a symbol of hope and change" for the country. She is at work but is keenly awaiting the moment when Kamala Harris takes the oath as the next vice president.

"I am - and I believe the WHOLE United States should be - looking forward to this monumental moment. She is making history! Not only as the first woman, but as the first woman of colour as well. I'm beyond ready, excited and proud to watch our VP take the oath."

Kamala Harris and her husband, Doug Emhoff, have just been formally announced, and have descended the Capitol steps to the podium where she will be sworn in shortly.

She will soon be the first female, black and South Asian vice-president in US history.

She is now standing beside outgoing Vice-President Mike Pence and greeting well-wishers.

Image source, Getty Images

Laura Trevelyan
BBC World News America presenter

It’s windy from our live position looking down on the White House, as the behind-the-scenes ritual is under way of preparing the president’s residence for the next occupant.

The pandemic and the circumstances of Donald Trump’s departure have made this tradition all the stranger.

A speedy deep clean of the residence is under way, now that the 45th president and first lady have left for Florida.

Staff have more time than usual to get ready for the next president, since Mr Trump is not attending the inaugural of his successor.

One tradition which Mr Trump is honouring - he’s left a note for Joe Biden in the Resolute desk, reportedly at the urging of his chief of staff Mark Meadows.

Not long to go now, and more senators, officials, and their guests are making their way to their seats ahead of the inauguration.

National youth poet laureate Amanda Gorman was also seen arriving. At 22, she will make history as the youngest ever inaugural poet.

Image source, Getty Images

Former US President Bill Clinton arrives with former Secretary of State Hillary Clinton.

Image source, Getty Images

Senator Bernie Sanders was spotted on his phone and keeping his hands warm on a cold January day.

Image source, AFP via Getty Images

Senate Majority Leader Mitch McConnell and former Secretary of Transportation Elaine Chao also made their arrival.

Image source, AFP via Getty Images

Katty Kay
World News America presenter

Image source, Getty Images

I was here in Washington on 9/11 when it came under attack in 2001.

But I have never seen this city in a lockdown like it is at the moment. Military Humvees on the roads, armed soldiers on street corners.

So today we have the weapons of war being used to secure the process of peace. I don’t recognise my city and it’s sad to see this.

Image source, Getty Images

Image source, Reuters

More attention than usual on the departing vice-president today, due to the absence of the president, of course.

Nick Bryant
BBC New York Correspondent

Today's ceremony will unfold on a platform that became a staging post two weeks ago when a pro-Trump mob stormed the US Capitol.

Normally the platform would be shoulder to shoulder with senators, family members and friends.

Of course now they're observing the protocols of coronavirus and social distancing.

We've not only had to come through massive security to get here - these past few days it has looked like Baghdad on the Potomac - we've also had to have coronavirus tests."

It's not the only break with tradition. Typically, the outgoing president would greet the incoming president at the front door of the White House. Donald Trump left by the back door.

We saw this extraordinary sight of Marine One flying over the inaugural stand on the way to Andrews Air Force Base where he had that rally before leaving for Florida.

There was this moment when the helicopter flew over us and it turned around and started heading back to the White House. It was almost as if he'd forgotten his wallet and he wanted to go back to get it.

Then we saw Trump's final ceremony unfold at Andrews. So Trumpian: the reality TV star staging his own finale, with Frank Sinatra's 'My Way' playing as he flew away on Air Force One.

America's inaugural ceremony prides itself on its bipartisan character - that hasn't happened this time around.

Here's what we're expecting to happen at the inauguration in the coming hour

• Biden and Harris have already arrived at the East Front Steps of the Capitol, the opposite side of the building that was raided by pro-Trump rioters two weeks ago. They were greeted by inaugural officials
• Former presidents are being announced as they arrive. Jimmy Carter, now in his 90s, is the only living president - besides Trump - who is not attending
• Around 11:30 EST (16:30 GMT), the invocation prayer is delivered by Jesuit Father Leo O’Donovan. Lady Gaga will then sing the National Anthem
• Harris will be sworn in as vice-president around 11:35 EST (16:35 GMT)
• A musical performance is next, from Jennifer Lopez
• Biden and his family will be introduced. He will be sworn in at 11:45 (16:45 GMT)
• Biden delivers his inaugural speech, which is expected to be about 20 minutes long
• A poem will then be read by Amanda Gorman before officials begin to depart the Capitol

Anthony Zurcher
BBC North America reporter

For the first time since Bill Clinton in the 1990s, the US will have a regular churchgoer as president.

Joe Biden, who is the nation’s second Catholic president, attends Mass almost every week. While in Wilmington, Delaware, during the long transition period, Biden would typically take the short motorcade from his home to Saturday service at St Joseph on the Brandywine. The small Catholic Chapel, one of the oldest churches in the area, is surrounded by tombstones of Irish and Italian immigrants from centuries ago - as well as the grave sites of two of Biden’s children and his first wife.

As president, it will be a greater challenge for Biden to move quickly to and from services, although there are a number of Catholic Churches - including St Matthews, where he attended Mass today - nearby.

The logistical and security challenges are part of the reason why regular church attendance has been less frequent for modern presidents. The Clintons frequently visited Foundry Methodist Church, and Jimmy Carter was a member - and Sunday school teacher - at First Baptist Church of DC.

George W Bush and Barack Obama only occasionally made appearances. Donald Trump may be best known for stopping by McClean Bible Church after a round of golf and standing outside St John’s Episcopal Church with a bible after Lafayette Square was forcefully cleared of Black Lives Matters protesters.

Eugene Goodman, the Capitol police officer who was hailed as a hero for steering the pro-Trump mob away from Senate chambers, is escorting Kamala Harris at the inauguration.

He is the new acting deputy House Sergeant at Arms according to US media.

You can read his story here

Joe Biden and Kamala Harris, with their spouses, have just been seen looking out over the National Mall, which would normally be filled with supporters if not for the pandemic.

Image source, Getty Images

Joshua Cheetham
BBC News

Image source, Getty Images

Before taking office, the constitution requires all presidents to swear an oath.

Franklin D Roosevelt has taken it a record four times, after winning four elections. But he shares this record with two-termer Barack Obama. So how does that work?

Back in 2009, during his first inauguration, Obama scuppered a key line after a mistake by Chief Justice John Roberts, who’d been administering the oath. So just to be sure, Obama did it again the next day.

His second inauguration, in 2013, was less dramatic. Since 20 January fell on a Sunday that year, Obama took the oath during a private ceremony in the White House, and then again in public the next day.

He’s not the first to slip-up with wording - five other presidents have done the same - but he’s the only one to do an oath again with corrections.

In 1929, an error in Herbert Hoover’s oath was discovered by a 13-year-old girl, Helen Terwilliger, who’d memorised the wording and was listening in on the radio.

She later wrote about it to Chief Justice William Taft, who admitted his mistake but insisted that it didn’t invalidate Hoover’s presidency.

We can expect Kamala Harris to become the first female vice-president in about 60 minutes now.

She will be sworn in by Supreme Court Justice Sonia Sotomayor, which is a history-making event in several ways.

The first black, South Asian and female vice-president will take her oath of office from the first Latina justice.

It’s reported that Harris chose Sotomayor for the task.

She will also use two Bibles for the swearing-in, one of which belonged to Thurgood Marshall, the first black Supreme Court justice.

Joe Biden will be sworn in by Chief Justice John Roberts, as is customary.