However, he was cautiously optimistic that a vaccine would be available until "late autumn, early winter".
Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, prepares to testify at a House subcommittee hearing in Washington, D.C., the United States, on July 31, 2020.
The U.S. has 4.7 million confirmed COVID-19 cases, the most in the world.
During his testimony Friday before a House subcommittee that's investigating the Trump administration's response to COVID-19, Fauci explained why he believed the USA was dealing with an ongoing surge of coronavirus infections, while European countries that were hardest-hit early on have seen more success in mitigating their spread.
'Wrong! We have more cases because we have tested far more than any other country, 60,000,000, ' Trump said in the afternoon tweet.
The United States has recorded almost 1.8 million new COVID-19 cases in July out of its total 4.5 million known infections, an increase of 66 per cent with many states yet to report on Friday.
"Yes, sir, I was", Fauci answered.
In his testimony, Fauci argues that a hesitancy to shut down more of the country made a baseline impact so that when the country "we were more vulnerable to a renewed surge in cases". "You should stay away from crowds, no matter where the crowds are".
"So this is why I keep coming back for the overall social [well-being] of individuals, is let's all work together and find out how we can find common ground to get these schools open in a way that people are comfortable and their safe". "If we had no testing, or bad testing, we would show very few CASES", he wrote on Twitter, adding: "This testing, and what we have so quickly done, is used as a Fake News weapon".
A new study, released Friday by the US Centers for Disease Control and Prevention (CDC), analysed 597 children and staff who attended an overnight camp in Georgia between June 21 and June 27.
And while most states in the US soon after followed suit, the Trump administration resisted calls to copy European countries and refused to put in place any sort of federally-mandated stay-at-home order.
"If you look at what's going on in this country, I just don't understand why we're not doing that", Dr.
This week, Trump, who has often bristled against scientists' advice on responding to the pandemic, bemoaned the degree to which Fauci is admired, saying "nobody likes me". Earlier this month, the White House blocked Redfield from testifying in the House, with a senior administration official telling reporters on condition of anonymity: "We need our doctors focused on the pandemic response".
"I'm not sure - how do you mean?"