The coronavirus-blighted southern US state of Arizona reported a record number of daily deaths as the country passed 50,000 cases in a day for the first time.
Hospitalisations rose in more than a dozen states and intensive care units in Houston, Texas, one of the worst-affected cities, were running out of room. Florida reported more than 10,000 new cases on Thursday, the biggest one-day increase in the state since the pandemic started.
Despite several days of record cases across the US, the White House rallied around efforts to get the economy moving again.
Donald Trump celebrated a report showing the economy created jobs at a record rate in June as more restaurants, bars and retail businesses reopened. Following the announcement of 4.8 million jobs, President Trump said: "Today's announcement proves that our economy is roaring back."
Arizona reported 4,900 new cases and 88 deaths, both daily records. The state's 1,495 intensive care unit beds were at 89 per cent capacity, and the number of ventilators in use at hospitals also hit a record high of 795. Doug Ducey, the state's Republican governor, reversed reopening plans, shutting all bars, gyms, cinemas and water parks.
He said: "We can't be under any illusion that this virus is going to go away on its own. Our expectation is that next week our numbers will be worse. It will take several weeks for the mitigation that we have put in place, and are putting in place, to take effect."
The US has so far reported more than 128,000 coronavirus-related deaths, nearly a quarter of the global total. Mr Trump has blamed the surge in cases on increased testing, but there has also been a rise in the percentage of positive tests, and hospitalisations.
At least 21 states have recently taken steps to pause or roll back reopening as the virus spreads in the south and west. California's governor, Gavin Newsom, a Democrat, closed bars, banned indoor dining, and imposed other restrictions in areas affecting 70 per cent of the state's population. He said: "The spread of this virus continues at a rate that is particularly concerning."
Texas again topped its previous daily record with 8,076 new cases. South Carolina reported 24 more coronavirus deaths, a daily record for the state. Tennessee and Alaska also had record numbers of new cases.
Eric Holcomb, Indiana's Republican governor, halted his state's phased reopening until at least mid-July. He said: "We just have to accept the fact that again this virus is on the prowl and it's moving even within our borders."
Mike Pence, the vice-president, said he and Mr Trump backed state governors in pausing reopening, but believed a national order forcing people to wear masks was unnecessary. Mr Pence also said he believed schools could reopen in the autumn.
Some states have issued their own orders to wear masks in public.
On Thursday, Kansas and Texas became the latest to do so. In Houston, Dr Joseph Varon, chief medical officer at United Memorial Medical Center, said: "In the last three weeks, I have seen more admissions and sicker patients than in the previous 10 weeks. It's been an exponential increase on the severity of illness and on the number of cases that we admit. Sooner or later, within the next two weeks, we're going to be at full house."
Sylvester Turner, Houston's mayor, said: "There is a severe and uncontrolled spread between our families, friends, and communities, and we need to slow it down so that it doesn't overwhelm our healthcare delivery system."
On Thursday night, the Governor of Texas made it mandatory for all Texans to wear a face covering of some kind while out in public. Greg Abbott said the order applied to all counties in Texas with 20 or more confirmed cases.
Meanwhile, the US National Institutes of Health said it was optimistic that Mr Trump's Operation Warp Speed, aimed at producing a vaccine, would generate a safe and effective one by the end of the year, and meet a target of 300 million doses by early 2021.
Dr Francis Collins, its director, said: "That's really a stretch goal, but it's the right goal for the American people."