Watch: US hits 25 million COVID-19 cases
The new milestone means the US accounts for roughly one in four cases reported worldwide and one in five deaths.
Earlier this week the US coronavirus death toll passed 400,000. It means the number of people who have died from Covid-19 is nearly equal to the number of Americans killed in the Second World War.
But the number of infections has shown signs of slowing recently, with an average of 176,000 reported daily in the past week, down from 244,000 in early January.
India has recorded the second most cases, with about 10.7 million.
The US government’s top infectious diseases expert said on Sunday that Joe Biden’s goal of administering 100 million vaccinations in the first 100 days actually means about 67 million Americans should be protected from Covid-19 during that time.
Anthony Fauci said the president’s goal refers to 100 million jabs, not people as the Covid-19 vaccines require two doses.
Dr Fauci acknowledged that goal could be difficult to meet even though the US has recently been able to administer jabs to about a million people a day.
He said it will be harder to reach people once vaccines are given outside hospital and nursing home settings.
Dr Fauci also said he supports a national commission to understand some of the problems in co-ordinating a Covid-19 response on state and local levels because states should not just be told, “You’re on your own’.
Hundreds of the nation’s intensive care units are running out of space and supplies, and competing to hire temporary travelling nurses at soaring rates, particularly in the South and West.
An Associated Press analysis of federal hospital data shows that since November, the share of hospitals nearing breaking point has doubled.
More than 40 per cent of Americans now live in areas running out of ICU space, with only 15 per cent of beds available.
Additional reporting by Associated Press.
Watch: Trump presented graphs 'I never made', says Dr. Birx