US Vice President Mike Pence has been forced to cancel re-election campaign events as the coronavirus surged in a number of battleground states.
The number of confirmed cases of COVID-19 in the country rose to more than 2.5 million on Saturday, according to a tally kept by John Hopkins University.
More than 125,000 Americans have so far died as a result of the coronavirus pandemic, the highest known number of deaths of any country in the world.
Florida saw a record second day of new infections with 9,585 cases on Saturday, while Arizona reported a further 3,591, matching a previous high.
In response, Mr Pence cancelled planned visits to campaign for the re-election of Donald Trump in those two states next week out of “an abundance of caution,” according to officials.
Meanwhile, Nevada recorded 1,099 new cases on Saturday, double its previous record, while South Carolina and Georgia saw 1,604 and 1,990 new infections, respectively, marking new daily highs.
The rise in cases has been seen most in a handful of southern and western states that reopened earlier and more quickly.
In contrast, New York and its neighbouring north-eastern states, which were initially hit hardest, have reported a fall in cases and are pressing ahead with reopening plans.
Kami Kim, director of the Division of Infectious Disease and International Medicine at the University of South Florida, said the state’s leaders had claimed victory too soon after lockdowns started to be lifted in early May, amid conflicting messages on face coverings.
She said: “It was just complete denial by a huge swathe of the politicians.
“Unfortunately, our community still isn’t taking it very seriously. People aren’t wearing masks.”
Despite the spike in cases, Florida’s Republican governor Ron DeSantis has not bowed to pressure to issue statewide mandates on wearing masks, opting to leave the decision to local areas.
He blamed the rise in infections on young people interacting more in the last few weeks, pointing out they faced a lower risk of dying than older people.
In Texas, a state that was on the forefront of letting people get back to work, Texas governor Greg Abbott ordered bars across the state to close and required restaurants to limit indoor seating, acknowledging that in hindsight he had opened bars too soon.