US President Joe Biden led Americans in observing a moment of silence to commemorate the grim milestone of more than 500,000 deaths from Covid-19, urging Americans to set aside partisan differences and fight the pandemic together.

“Today we mark a truly grim, heartbreaking milestone - 500,071 dead. That's more Americans who have died in one year in this pandemic than in World War One, World War Two and the Vietnam War combined,” Biden said in emotional remarks at the White House.

“But as we acknowledge the scale of this mass death in America, we remember each person and the life they lived. They're people we knew.”

Biden, Vice President Kamala Harris, first lady Jill Biden and second gentleman Doug Emhoff marked a moment of silence outdoors at the White House after the president's remarks, bowing their heads somberly.