US President Joe Biden gave a sombre address to the nation as the country marked the 'grim milestone' of more than 500,000 Covid deaths.
The United States on Monday crossed the staggering milestone just over a year since the coronavirus pandemic claimed its first known victim in Santa Clara County, California.
In a proclamation honouring the dead, President Joe Biden ordered the US flag to be flown at half-staff on public buildings and grounds until sunset on Friday.
He said: "On this solemn occasion, we reflect on their loss and on their loved ones left behind. "We, as a nation, must remember them so we can begin to heal, to unite, and find purpose as one nation to defeat this pandemic." Bells also tolled at the National Cathedral in