But even as cases spike around the country, Mr. Pence tried to take a victory lap, asserting, “We slowed the spread, we flattened the curve, we saved lives.”

Mr. Pence was joined by top members of Mr. Trump’s coronavirus task force, including Dr. Anthony S. Fauci, the nation’s top infectious disease expert, and Dr. Birx.

The session is a significant re-emergence for the task force, whose health officials, at one point, gathered every day for long hours as death rates peaked around the country, and offered a public briefing that allowed for questions from reporters. But they have been largely sidelined at the White House even as the United States on Thursday reported more than 41,000 new coronavirus cases, a record total for the second straight day.

Despite the staggering numbers, Mr. Trump — who did not attend Friday’s session — has been trying to declare the pandemic “over.” Around midnight Friday, he wrote on Twitter, “Our Economy is roaring back and will NOT be shut down. ‘Embers’ or flare ups will be put out, as necessary!”

Half of new cases are affecting Americans younger than 35, which Mr. Pence described as “good news,” because younger Americans are less likely to fall seriously ill. However, Dr. Fauci has noted that the nation must not be sanguine about infections in young people, because some do suffer serious effects.

People 18 to 44 have represented nearly half of the total cases in the U.S. since the start, according to figures from the Centers for Disease Control and Prevention. Of 2 million people who have tested positive, 1.6 million were under 65.

In testimony early this week, Dr. Fauci flatly contradicted Mr. Trump, stating, “The virus is not going to disappear.”