Democrat Joe Biden was sworn in as president of the United States on Wednesday, vowing to end the 'uncivil war' in a deeply divided country reeling from a battered economy and a raging coronavirus pandemic that has killed more than 400,000 Americans.

With the US Capitol encircled by thousands of armed troops two weeks after a mob laid siege to it, Biden took the oath of office administered by US Chief Justice John Roberts and became the oldest US president in history at age 78.

He was sworn in moments after Kamala Harris, who became America's first woman vice president, turning the page on Donald Trump's tumultuous four years.

With the general public essentially barred from attending due to the pandemic, Biden's audience at the National Mall instead was 200,000 flags planted to represent the absent crowds.

Biden nonetheless brought in star power — absent four years ago with Trump. Lady Gaga sang the national anthem and Tom Hanks prepared for a televised evening appearance with the new president.

Header image: President-elect Joe Biden congratulates Vice President Kamala Harris and her husband Doug Emhoff after taking her oath of office during the 59th Presidential Inauguration at the US Capitol in Washington. — AFP