There have now been at least 28 million confirmed cases of Covid-19 across the country since the virus was first identified in North America in January 2020.
The grim milestone, which is more than double any other nation, was reached on Monday, according to data collated by Johns Hopkins University.
The number of deaths in the US has doubled in just three months, as the country only passed 250,000 fatalities from coronavirus on 18 November, 2020.
Joe Biden said “that is more Americans who have died in a single year of this pandemic than in World War I, World War II, and the Vietnam War combined.”
“On this solemn occasion, we reflect on their loss and on their loved ones left behind,” he said. “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.”
The president will hold a memorial service with a moment of silence and a candle-lighting ceremony on Monday evening. He has also ordered flags at half-mast for five days.
New Covid-19 cases hit a peak in the US after the Christmas holiday period, as the country recorded an all-time high on 8 January with 300,619 cases, with a seven-day average of 259,971.
The peak for US deaths from Covid-19 came a month later, when the country recorded 5,463 fatalities on 12 February, with a seven-day average of 3,352.
Although the number of deaths from the virus has fallen in recent days, the latest forecast from the University of Washington’s Institute for Health Metrics and Evaluation (IHME) projects 91,000 more Americans could die from Covid-19 by 1 June.
“The most uncertain driver of the trajectory of the epidemic over the next four months is how individuals will respond to steady declines in daily cases and deaths,” the IHME research team wrote.
“More rapid increases in mobility or reductions in mask use can easily lead to increasing cases and deaths in many states in April,” the researchers added.
The administering of coronavirus vaccines across the US will help the country tackle the virus, as the president has said that he expects the US to provide enough doses to vaccinate 300 million Americans by the end of the summer or early autumn.
So far, around 43 million Americans have received the first dose of their coronavirus vaccine, while 5.5 per cent of the US population is already fully vaccinated.
Brazil has recorded the second highest amount of deaths from Covid-19, with 245,977, while Mexico has seen 179,197, India has had 156,302 fatalities and the UK has recorded 120,595.
However, San Marino has the highest number of deaths per 100,000 people, while the US is behind seven other countries, including the UK, Italy and Portugal on that measure.
Globally, more than 111.2 million people have been infected by the coronavirus. The worldwide death toll now exceeds 2.46 million.