President Trump on Friday began his first trip since returning to the White House to storm-ravaged North Carolina and California, which is facing some of the most deadly and destructive blazes in the state’s history.

The trip comes as the president has left the question of additional disaster aid for California unsettled.

Mr. Trump is expected to make his first stop in Asheville, N.C., which had devastating flooding from Hurricane Helene last fall. The president then plans on traveling to the Los Angeles area, where he will observe the damage from wildfires that have killed more than two dozen people, destroyed entire neighborhoods and forced desperate evacuations.

But Mr. Trump has struck very different tones on the likelihood of additional federal aid for each state. While he has expressed support for North Carolina, Mr. Trump has criticized California’s Democratic leaders for the disaster response and threatened to withhold federal aid if they did not make changes to unrelated environmental policies in the state.

“It’s been a horrible thing the way that’s been allowed to fester, and we’re going to get it fixed up,” Mr. Trump told reporters of the previous administration’s disaster recovery effort. “North Carolina’s been treated very badly, so we’re stopping there.”

For the Los Angeles stop, Mr. Trump said he wanted “to take a look at a fire that could have been put out if they let the water flow, but they didn’t let the water flow, and they still haven’t.”

“We’re going to have a very interesting time,” he said.

Presidents have typically visited areas recovering from natural disasters to show personal support and assure community members of federal aid for emergency medical workers and local leaders. Mr. Trump, however, has often used natural disasters as a vehicle to unleash political grievances, threatening to withhold money from political opponents, making false statements about disaster responses by Democrats and promising support for political allies.

During Mr. Trump’s first term, he told aides he wanted to stop money from reaching Puerto Rico after Hurricane Maria, claiming that the island’s leadership was corrupt. After wildfires erupted in California in 2018, Mr. Trump said on social media that he had ordered the Federal Emergency Management Agency to “send no more money” unless the state changed its approach to forest management.

Before traveling on Friday, Mr. Trump had already displayed different approaches to California and Republican-led North Carolina.

“We’re going to get that thing straightened out because they’re still suffering from a hurricane from months ago,” Mr. Trump said in a taped interview with Fox News that aired on Wednesday night.

Since the early days of the hurricane response, Mr. Trump has made a number of accusations about the Biden administration’s response to Hurricane Helene that were debunked by the local, state and federal authorities in the disaster areas.

The false statements included claims that FEMA had spent huge sums on housing for migrants and that it had told victims of the storms they would receive only $750. The string of false claims prompted President Joseph R. Biden Jr. to accuse Mr. Trump of spreading “outright lies.”

In the same interview with Fox News, Mr. Trump issued broadsides against Gavin Newsom, California’s Democratic governor — whom the president has called “Newscum” — for his management. He also threatened to withhold disaster aid for wildfires unless the state changed environmental policies that he claimed had prevented enough water from going to Southern California.

“I don’t think we should give California anything until they let water flow down,” Mr. Trump added.

State and fire experts have said those policies have no connection to the fires in the Los Angeles area.

During a news conference on Thursday, Mr. Newsom expressed confidence that the Trump administration would still reimburse California for the disaster-related funds. He added that he planned to be at the airport to greet Mr. Trump, even though he did not know whether he would be invited to accompany the president during his tour of the Los Angeles area.

While Mr. Newsom was left in the dark, Mr. Trump appeared to extend last-minute invitations to Senators Adam B. Schiff and Alex Padilla, Democrats of California, to join him in his visit to the state, days after calling Mr. Schiff “scum” on Inauguration Day.

A spokesperson for Mr. Schiff, with whom Mr. Trump has long had an acrimonious relationship, said on Thursday that the senator would not be able to make the trip because of expected Senate votes on cabinet nominees.

“Senator Schiff greatly appreciates the president’s visit to see the devastation of these wildfires firsthand and the invitation to accompany him,” the spokesperson said in a statement. The statement added that Mr. Schiff would work with Mr. Trump’s team and other officials “to ensure that California gets the aid and support it needs.”

Mr. Padilla will also not join Mr. Trump because of the Senate vote schedule, his spokeswoman said, but he welcomed Mr. Trump’s support “for federal disaster aid to assist the thousands of families and businesses impacted by these devastating fires.”

Annie Karni contributed reporting.