As Mr. Trump has had to reverse himself on his overly upbeat assessments of how quickly he could reopen the country for business, he has also increasingly targeted some of his regular foils.

On Monday morning, in an interview with “Fox & Friends,” he referred to Speaker Nancy Pelosi as a “sick puppy” after she had appeared on CNN’s “State of the Union” and said the president’s early denials about the dangers of the coronavirus carried “deadly” consequences.

“As the president fiddles, people are dying,” Ms. Pelosi said.

In an interview on Monday, she rolled her eyes at his attack. “Every knock from him is a boost for me, quite frankly, so I don’t care what he says,” she said.

And at his Sunday evening news conference, Mr. Trump snapped at Yamiche Alcindor, a PBS NewsHour correspondent whom he has criticized publicly in the past, for asking him to defend his own statements about governors making requests for medical equipment like ventilators that he believes they do not actually need.

“Let me tell you something,” Mr. Trump said, after denying he made statements that he had, in fact, made. “Be nice. Don’t be threatening. Don’t be threatening. Be nice.”

Ms. Alcindor tweeted in response that she was “not the first human being, woman, black person or journalist to be told that while doing a job.”

It was a sentiment echoed by Democrats, who said Mr. Trump’s pattern of singling out women for critiques ultimately takes a toll on him politically with female voters, even as it energizes some members of his base.