Alabama and several other US states have reported record daily increases in coronavirus cases as Florida's most populous county imposed a curfew ahead of the Independence Day weekend.
North Carolina, South Carolina, Tennessee and Alaska all saw new daily highs in confirmed cases of COVID-19, while Florida's caseload came in just below the prior day's record high.
Coronavirus cases are rising in 37 of the 50 US states.
The surge in cases in southern and western states has alarmed public health officials, who urged caution ahead of the July 4th holiday weekend.
Despite the jump in infections, the daily death rate in the United States has remained relatively flat, a reflection of the growing proportion of positive tests among younger people who tend to be less prone to severe outcomes.
However, US Surgeon General Jerome Adams warned that fatalities from the recent surge were still to come. "Deaths lag at least two weeks and can lag even more," he told "Fox & Friends" on Friday.
His remarks came hours ahead of a trip by President Donald Trump to Mount Rushmore in South Dakota where he is due to deliver a speech to thousands of supporters at the landmark, which depicts four US presidents in stone.
The visit has drawn criticism from Native Americans, who say the remote area is sacred to them, as well as health experts who discourage large gatherings.
Trump has repeatedly sought to dismiss the jump in cases as a function of more testing and again this week said he thought the virus would "disappear."
Coronavirus cases are rising in 37 of the 50 US states including Florida which had 9,488 new cases on Friday, according to the state health department. Florida's 10,109 cases on Thursday was a record for the state and more than any European country's daily peak at the height of the outbreak there.
Evidence the surge is not simply due to expanded testing, the percentage of tests coming back positive in Florida has risen to 16 per cent, up from 4 per cent a month ago, according to a Reuters analysis. The World Health Organisation says a rate over 5 per cent is concerning.
Against that backdrop, Miami-Dade County Mayor Carlos Gimenez imposed an indefinite nightly curfew starting Friday and halted the reopenings of entertainment venues such as casinos and strip clubs, while urging people to act responsibly.
Earlier this week, Miami-Dade and neighbouring Broward County, the state's two most populous counties, required residents to wear face coverings in public.
Arkansas Governor Asa Hutchinson on Friday authorised the state's cities and towns to enact a "model ordinance" requiring the wearing of face coverings if they choose to do so. The move follows similar but more sweeping mask-wearing requirements by Texas and several other states this week.
Australian Associated Press