President Biden warned on Thursday that Florida was in for “a long haul” after Hurricane Milton, and for a second day in a row he singled out former President Donald J. Trump for spreading misinformation, telling him to “get a life, man.”

Speaking from the White House, Mr. Biden also issued a direct appeal to Congress to help disaster recovery agencies. His administration said that the Federal Emergency Management Agency had enough funding to respond in the short term to disasters, but that it would need help for longer-term recovery.

“We know from previous hurricanes that it’s often the case more lives are lost in the days following the storm than actually during the storm itself,” Mr. Biden said. “It’s going to take several billion dollars,” he added. “It’s not just going to be a matter of just a little bit.”

Mr. Biden also said Congress should come back from its recess specifically to help the Small Business Administration, which has warned that it will soon run out of funding to issue loans for homeowners and businesses affected by the storms.

“In terms of the S.B.A., it’s pretty right at the edge right now and I think the Congress should be coming back and moving on emergency needs immediately,” Mr. Biden said.

The White House is juggling the response to two devastating storms in the past two weeks while rebutting misinformation from Mr. Trump and some of his allies, something that Mr. Biden and Vice President Kamala Harris have tried to counter in recent days.

“They’ve got to stop this,” Mr. Biden said. “I mean, they’re being so damn un-American with the way they’re talking about this stuff.”

Mr. Trump has claimed falsely that FEMA told victims of recent natural disasters they would receive only $750. Speaking directly into the camera, Mr. Biden implored Mr. Trump to “get a life, man. Help these people.”

Mr. Biden did indicate that efforts to get residents to evacuate worked. More than 80,000 people followed orders to safely shelter, and more than 1,400 federal search-and-rescue officials were deployed to the state.

Earlier on Thursday, Alejandro N. Mayorkas, the homeland security secretary, appeared by video at the White House press briefing to give an update on Hurricane Milton from North Carolina, where he is still overseeing the response to Hurricane Helene.

He said that FEMA had what it needed to respond effectively if another hurricane emerged in the coming weeks, but that the agency would eventually need help from Congress.

“We have the capability and the capacity to respond to and recover from multiple simultaneous disasters,” Mr. Mayorkas said, adding that no resources from the response to Helene would be diverted to the response for Milton in Florida.

“Milton may have passed, but the danger it poses has not,” Mr. Mayorkas said.