WASHINGTON — President Trump has pledged to donate $1 million from his personal fortune to storm victims in Texas and Louisiana.

“He would like to join in the efforts that a lot of the people that we’ve seen across this country do,” Sarah Huckabee Sanders, the White House press secretary, said Thursday during her daily briefing at the White House.

Ms. Sanders said the president has not decided when or where he will send the donation.

“He actually asked that I check with the folks in this room, since you are very good at research and have been doing a lot of reporting into the groups and organizations that are best and most effective in helping and providing aid, and he’d love some suggestions from the folks here and I’d be happy to take those,” she told reporters.

Mr. Trump’s pledge is one of the largest financial commitments made by a sitting president to a charitable cause. Ms. Huckabee, pressed by reporters, said she wasn’t sure whether the donation would come from Mr. Trump’s foundation or his own bank account, saying only that it would come from the president’s “personal” funds.

The size of Mr. Trump’s fortune has been a topic of ferocious debate, with the president estimating it at more than $10 billion, and outside analysts calculating it to be much less. But Mr. Trump reportedly donates far less of his income and assets than many of his ultra wealthy peers, and this donation comes with questions attached. In the past, he has failed to follow through on promised donations from his nonprofit foundation.

The commitment is part of a larger campaign to urge Americans to donate to charities involved in the recovery effort from Harvey. Mr. Trump’s campaign organization sent out an email on Tuesday requesting cash contributions to a range of charities in the Gulf.

Mr. Trump traveled to Corpus Christi and Austin on Tuesday and he is tentatively planning to visit the Houston area as well as Louisiana on Saturday, according to Ms. Sanders.

The president’s trip to Corpus Christi consisted of meetings with local, state and federal officials in a city that was largely spared by the lashing rains and historic flooding that ravaged Rockport, Galveston, Port Arthur and Houston.

Mr. Trump claimed to witness “first hand the horror & devastation caused by Hurricane Harvey” but he saw little of the damage.

Vice President Mike Pence toured harder-hit areas on Thursday, consoling people displaced by the floods with hugs and joining Governor Greg Abbott of Texas in clearing up debris. At one point, Mr. Pence was photographed heaving large branches onto a pile of shredded brush.