Dr. Anthony Fauci also urged Americans to take the virus more seriously as infections surge in multiple states.
He called out Vice President Mike Pence for his comments about reopenings and the state of the USA coronavirus response that "simply do not square with the facts".
Pence said that what federal officials are observing in Florida, Texas and some other states is more people under 35 years old testing positive.
The Vice President was also questioned about the President's recent rally in Oklahoma.
Before the latest daily case count surpassed 40,000, data from Johns Hopkins University showed that 39,972 new cases were confirmed Thursday, exceeding the previous high of 36,291 in April.
As criticism mounts that the White House has turned a blind eye to the worsening coronavirus epidemic in the South and West, Vice President Mike Pence is arguing that the administration remains on top of the response.
Pence described the Sun Belt situation as particularly "epidemic" in "specific counties" and "specific communities" - declining to emphasize that, as expert Dr. Peter Hotez said on CNN after the briefing, the posts experiencing a "massive resurgence" include some of the country's most populous counties. "We are facing a serious problem in certain areas", said Dr. Fauci.
Or, that 34 states across the country are seeing "a measure of stability", which is false since cases are on the rise in more than half the states.
The Florida agency that governs bars acted after the daily number of confirmed cases in the state neared 9,000, a record that was nearly double the previous mark set just two days earlier.
Texas, along with states such as California and Florida, has recently been reporting thousands of new cases each day. Various states and thousands of out-of-state health care workers helped NY when it was in the throes of the deadliest outbreak in the nation this spring.
The top USA infectious disease specialist called on young people to accept "societal responsibility" amid a surge of positive tests for coronavirus. Texas had announced hours earlier that it had to shut down in-person service at its bars again. Trump, who faces reelection and is pushing to reopen the economy even as his own experts call on Americans to be cautious. Arizona reported over 3,000 additional infections Thursday, the fourth day in a week with an increase over that mark. The same month, he toured a mask factory without wearing a mask. In addition to prayer, according to health officials, Americans can prevent a spike in deaths by staying away from each other and covering their mouths when in public.
'I think it is important that people recognize how important freedom and personal responsibility are to this entire equation'.