Health workers protest outside the hospital to demand management take immediate measures to protect them from further infection in California on Thursday. AFP

Fatalities nationwide were recorded at 1,118 on Thursday. Deaths were 1,135 on Wednesday and 1,141 on Tuesday.

Even though deaths are rising in the United States for a second week in a row, they remain well below levels seen in April, when 2,000 people a day on average died from the virus.

A female police officer jokes with Ivanka Trump at Rocky Mountain National Park. AP

The United States on Thursday also passed a total of more than 4 million coronavirus infections since the first US case was documented in January, according to a Reuters tally, reflecting a nationwide escalation of the pandemic.

The United States took 98 days to reach one million confirmed cases of COVID-19 but just 16 days to increase from 3 million to 4 million, the tally showed. The total suggests at least one in 82 Americans have been infected at some point in the pandemic.

The average number of new cases is now rising by more than 2,600 per hour nationwide, the highest rate in the world.

As the epicentre of the US outbreak has spread from New York to the South and West, federal, state and local officials have clashed over how to ease lockdowns imposed on Americans and businesses.

Requirements that residents wear masks in public have become the subject of a fierce political divide, as many conservatives argue that such orders violate the US Constitution.

US President Donald Trump, a Republican who has rejected a nationwide mask rule and been reluctant to wear one himself, this week reversed course and encouraged Americans to do so.

'WEAR A MASK, AVOID CROWDS'

"We have to do our mitigation steps: Wear a mask, avoid the crowds. We won't see hospitalisations and deaths go down for a couple of weeks because (they are) lagging indicators, but we are turning that tide," US Assistant Secretary for Health Brett Giroir told the Fox News Network in an interview.

Trump told a White House briefing on Thursday that hot spot states may need to delay re-opening schools by a few weeks but pushed for most students to be able to return to classrooms in the fall.

Schools have become another point of contention. In Florida, the state teachers' union has sued to stop in-class instruction. Florida reported a record one-day increase in COVID-19 deaths on Thursday at 173.

Florida's health commissioner said earlier this month that schools must reopen, but Governor Ron DeSantis, a Republican, has since said that parents should have the option to keep their children home.

Trump administration officials have said a quicker reopening is essential to get the staggered economy moving again, a central plank of the president's re-election campaign.

Trump also said he would no longer hold part of the Republican Party's nominating convention in Florida in August because of a spike in coronavirus cases in the state.

"The timing for this event is not right," Trump told the White House briefing. "It's just not right with what’s happened recently, the flare-up in Florida. To have a big convention it’s not the right time."

Reuters