Trump retweeted a message on Sunday from a former Republican congressional candidate who cited Fauci's comments during a television interview on Sunday and tweeted "time to #FireFauci."

The Republican president in the past has repeated critical tweets of officials or enemies rather than make the criticism himself. The retweet fuelled speculation Trump was running out of patience with the popular scientist and could conceivably fire him.

The White House did not immediately return a request for comment on whether Trump is unhappy with Fauci.

Fauci has assumed national prominence as a leader in the fight against the coronavirus. He has contradicted or corrected Trump on scientific matters during the crisis, including whether the anti-malaria drug hydroxychloroquine is effective against it.

Fauci was asked on CNN's "State of the Union" about a New York Times report documenting early warnings issued to the White House about the novel coronavirus. The scientist acknowledged shutting the country down sooner could have saved lives, but cautioned that a number of factors were involved.

"Obviously, it would have been nice if we had a better head start, but I don't think you could say that we are where we are right now because of one factor," Fauci said. "It's very complicated."

Already a target of the far-right for his contradictions of Trump, Fauci drew more opprobrium after the comments.

Trump also denounced the New York Times story in several tweets on Sunday, calling it "A Fake."

Last week during the daily White House coronavirus briefing, Trump stepped in and prevented Fauci from answering a question about hydroxychloroquine.

Fauci, 79, has led the federal infectious disease agency since 1984 under Republican and Democratic presidents. Republican George W. Bush honoured him with the presidential Medal of Freedom in 2008.

Some polls during the public health crisis have shown Americans trust him more than Trump.

Australian Associated Press