'On the brink': US coronavirus cases surge in final days before election

The US is surging towards record numbers of new coronavirus infections above 100,000 a day, health experts have warned, just as a presidential campaign with the pandemic as its core issue enters its final week.

Related: US nears daily Covid cases record amid warning of 500,000 deaths by February

In a further blow to Donald Trump’s hopes of keeping the White House, the US death toll from Covid-19 will pass 225,000 by early this week, bringing extra scrutiny to the president’s repeated but evidently false claims that the crisis is “rounding the turn”.

With only 10 days remaining before election day, 3 November, and with more than 56 million Americans having voted by mail or in person, the Republican incumbent is short on time and resources to convince a dwindling number of undecideds he is the best choice to lead the country out of the pandemic.

National polls continue to show Democratic challenger Joe Biden with a substantial lead, although the races are noticeably tighter in several of the crucial swing states both candidates need to secure victory in the electoral college.

The country set a record daily number of new coronavirus cases on Friday at more than 83,000, eclipsing the previous high set on 16 July by more than 6,000. Dozens of states have reported surges in numbers. The Republican governor of Utah, Gary Herbert, warned that health services are at breaking point.

“Up until now, our hospitals have been able to provide good care to all Covid and non-Covid patients who need it,” he said. “But today we stand on the brink. If Utahans do not take serious steps to limit group gatherings and wear masks, our healthcare providers will not have the ability to provide quality care for everyone who needs it.”

Health experts see the crisis worsening, in contrast to the rosy picture painted by Trump at campaign rallies that the US is “rounding the corner beautifully” and will not see the dark winter Biden foresaw in this week’s final presidential debate.

“We easily will hit six-figure numbers [daily] in terms of the number of cases,” Michael Osterholm, the director of the center for infectious disease research and policy at the University of Minnesota, told CNN. “And the deaths are going to go up precipitously in the next three to four weeks, following usually new cases by about two to three weeks.”

Related: California ‘shattering prior election returns’ with 6m ballots already cast

Trump was in his home state of Florida on Saturday, casting his vote at a library in West Palm Beach – “I voted for a guy named Trump,” he told reporters – before departing for large campaign rallies in North Carolina, Ohio and Wisconsin. On Sunday he will speak in New Hampshire.

Biden has maintained a less frantic schedule, preferring smaller, drive-in or virtual events. Aides have said he will be “campaigning aggressively” in battleground states in the coming days, and he was scheduled to appear at two drive-in events in Pennsylvania on Saturday, one attended by the singer Jon Bon Jovi.

At the first event, in Bristol, Biden addressed supporters gathered in pickups or cars, many with windows or sunroofs down.

“It’s going to be a dark winter ahead unless we change our ways,” he repeated.

Biden was due to get some help from former President Barack Obama, who was to hold a drive-in rally in Miami. Obama delivered a blistering attack on Trump’s leadership on Wednesday in Pennsylvania, his 2020 campaign debut.