President-elect Joe Biden will lay a wreath in the presence of three former US presidents at Arlington National Cemetery directly after his swearing-in, part of a theme centred on unity that his inauguration committee announced Monday.

The ceremony itself will unfold before a National Mall filled with flags rather than the usual hundreds of thousands of spectators, with normal celebrations hobbled by the coronavirus pandemic, which has killed more than 370,000 people in the US, the world’s largest death toll.

The announcement of the inauguration’s “United America” theme came less than a week after a mob of supporters of outgoing President Donald Trump ransacked the US Capitol building, including the stage area on which Biden is to be inaugurated.

Former presidents Barack Obama, George W. Bush and Bill Clinton will join Biden and Vice President-elect Kamala Harris as they lay a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery.

Every four years spectators fill the National Mall, the enormous lawn stretching blocks before the Capitol, which will be dotted by approximately 191,500 flags of varying sizes, including from US states and territories, according to the inauguration committee.

Biden immediately faces the herculean task of healing wounds in a country plagued by economic and health crises, a highly divided electorate and undergoing a moment of racial tension and reconciliation.

Trump has announced he will not attend the inauguration, which Biden has called “a good thing.” However, Vice President Mike Pence will reportedly be there.

The only other living US leader to skip the ceremony is former Democratic president Jimmy Carter, who is 96 years old.