“He believes that we have to bring this country together,” incoming White House communications director Kate Bedingfield said on ABC’s This Week on Sunday. “You can expect that this will be a moment where President-elect Biden will really work to try to turn the page on the divisiveness and the hatred of the last four years.”

The inaugural address will be the highest-profile speech of Biden’s nearly half-century in politics. While he will soberly address the difficult challenges ahead, his remarks were expected to be optimistic, stressing that with the right policies and a glimmer of comity in Washington, the country can find its way to a better position than before the pandemic.

The speech is likely to contrast markedly from Trump’s inaugural address in 2017, in which he famously declared he would end “American carnage” in the streets of US cities.

Ron Klain, the incoming White House chief of staff, said Biden would sign more executive actions on his first day than any other president, in part to overturn policies unilaterally adopted by Trump. They’re expected to include orders to end a ban on travel from some predominantly Muslim nations and to rejoin the Paris climate accord.

Biden’s inauguration as the 46th US president will be unlike any other in modern history. Washington DC is now a fortified city, with rings of security around the Capitol, White House and National Mall and thousands of armed soldiers guarding against another attack by Americans who refuse to accept Trump’s defeat.

While the outdoor ceremony is “certainly our plan,” Biden’s team is “preparing for any scenario” surrounding the inauguration, Bedingfield said.

Kamala Harris, who will be sworn in as vice-president, also recognised the unique nature of Wednesday’s ceremony.

“This will be an inaugural like no other, in large part because of Covid,” Harris said in an interview aired Sunday on CBS.

“But we are going to get sworn in. And we’re going to do the job we were hired to do.”

Previous well-attended inaugurations saw more than one million people descend on Washington.

This year there will be no place to go: a sea of 200,000 flags on the National Mall will stand in for the normally vast crowd cheering a new commander in chief.

As is traditional, lawmakers, top government officials, justices of the Supreme Court, and other dignitaries will gather on the Capitol building’s grand west front for Wednesday’s ceremony.

Given the need for social distancing, the crowd will likely be thinner than usual, and all masked.

There will be the traditional invocations and benedictions by church leaders.

In between, Lady Gaga will deliver the national anthem, 22-year-old African American poet Amanda Gorman will read one of her works, and Jennifer Lopez will sing.

At midday, Supreme Court Justice John Roberts will give Biden the oath of office, and Harris will be sworn in by Justice Sonia Sotomayor.

Traditionally, an outgoing president and previous presidents attend inaugurations, underscoring unity and the democratic transfer of power.

This year, ex-presidents Bill Clinton, George W. Bush and Barack Obama will be on the dais. Jimmy Carter, 96, is staying home, given the pandemic.

Glaringly absent will be Trump, who spent the past two months claiming Biden won the election by fraud.

Planning to leave Washington for his Mar-a-Lago club in Florida that morning, he will be only the fourth president to skip the event. The last was in 1869. But outgoing Vice-President Mike Pence will attend.

That also means there will be no traditional welcoming to the new occupants of the White House by the departing homeowners.

Some traditions will remain, however, and some more modern elements will also continue. A briefcase known as the “nuclear football” containing the codes to launch nuclear weapons will be handed from one aide to another, and the White House website and social media handles will switch automatically.

An inauguration is nothing without parades, parties and concerts, and Biden and Harris have not forgotten - but this year everything will be online or televised.

Five days of events are planned, with multiple-artist concerts on Saturday, Sunday and Monday.

On inauguration day they will hold a “Parade Across America”, an online 50-state tour of speakers, artists and performers.

The main event on Wednesday night stars John Legend, Bruce Springsteen, Justin Timberlake, Ant Clemons, the Foo Fighters and Demi Lovato.

And for at-home parties, there is a curated “Biden+Harris Playlist”. True to the new US leader’s age, 78, it spans nearly six decades.

Bloomberg and Agence France-Presse