Reading from prepared remarks, Mr. Trump said that “all of America grieves” for those who have already lost their lives from Hurricane Irma, and he urged people in Florida to heed the directions offered by state and local authorities.

“This is a storm of enormous destructive power. I ask everyone in the storm path to heed all instructions. Get out of its way,” he said, adding: “Property is replaceable, but lives are not, and safety has to come first. Don’t worry about it. Just get out of its way.”

Mr. Trump said that he planned to discuss other topics with his cabinet as well, including what he called “the latest provocative and destabilizing actions of North Korea” and the need for an overhaul of the nation’s tax code.

He said the tax effort would seek to lower rates and bring back capital parked by businesses overseas because of high business tax rates in the United States. He said that would amount to “in the neighborhood of 4 to 5 trillion” dollars.

Mr. Trump is scheduled to return to the White House on Sunday afternoon. Officials said that Mr. Trump would receive a teleconference briefing on the hurricane at 10 a.m. before he returned to Washington.

On Friday, administration officials expressed confidence that the Federal Emergency Management Agency had the resources to respond to Hurricane Irma even as it continues to deal with the aftermath of the flooding in Texas and Louisiana from Hurricane Harvey.

“I’m pretty comfortable in our ability and our capacity as leaders, but also as institutions to handle the various different things that come our way,” said Thomas P. Bossert, the president’s Homeland Security adviser.

In his address, Mr. Trump pledged that “we will endure and come back stronger than ever before.” But in a tweet later Friday night, Mr. Trump raised concerns with a longstanding policy that prevents FEMA from providing grants to houses of worship that are damaged by hurricanes and other natural disasters.