“I like him, he is terrific,” the president said, claiming he was merely elevating someone else’s opinion he did not share. “Not everybody is happy with Anthony, not everybody is happy with everybody.”

Mr. Trump’s tweet was part of a weekend-long effort to defend himself against criticism of his slow initial response to the pandemic. The president arrived in the briefing room with a video reel of cable news excerpts showing journalists and Democratic governors complimenting his decision to institute China travel restrictions in late January, and of other experts playing down the threat of the coronavirus.

His anger appeared to also be directed at Dr. Fauci, who on Sunday appeared on CNN’s “State of the Union,” where he said more lives could have been saved from the coronavirus if the country had been shut down earlier. “I mean, obviously, you could logically say that if you had a process that was ongoing and you started mitigation earlier, you could have saved lives,” Dr. Fauci said.

On Monday, he said the response was taken out of context as confirmation of a New York Times investigation that reported the president was warned about the potential for a pandemic but lack of planning led to a halting response.

“As happens all the time, there were interpretations of that response to a hypothetical question,” Dr. Fauci said. “I thought it would be nice for me to clarify because I did not have a chance to clarify.”