Coronavirus infections across the United States have passed 2.5 million, with record numbers of cases reported in the states of Florida and Texas.
The surge in cases in southern states comes after businesses were allowed to re-open in recent weeks.
On Saturday, Florida reported more than 9,500 new cases, up from almost 9,000 on Friday, the previous record.
The spike has led state officials to tighten restrictions on business again - as Texas also did on Friday.
The leading US government adviser on coronavirus, Dr Anthony Fauci, said last week that the country had a "serious problem".
More than 125,000 Covid-19 patients have died nationwide - more than in any other country.
Speaking at the first White House coronavirus task force briefing in two months, Dr Fauci said on Friday that the current rises were due to regions "maybe opening a little bit too early" and to people themselves not following guidance.
"People are infecting other people, and then ultimately you will infect someone who's vulnerable," he said.