“We have the best property in Washington D.C.,” he said on Saturday. “People like the brand.”

Ethics lawyers said that even if the White House and the president were not overtly pressuring individuals seeking help from the federal government to visit a Trump brand, the pattern was still troubling.

“The danger from the beginning was less that the president would press people to stay at his hotel,” said Noah Bookbinder, a former federal prosecutor who is now executive director of CREW. “But people in the administration, congressional allies, industry executives, foreign government leaders — they see that the president reacts favorably to people doing business with him. So they do it.”

The visits that have drawn perhaps the most scrutiny are those by officials of foreign governments. Their frequency has led to allegations that Mr. Trump is violating the so-called emoluments clause of the Constitution by accepting foreign government funds.

The single biggest known tab was paid by the government of Saudi Arabia, which disclosed that it spent $190,273 at the Trump hotel in early 2017, as well as an additional $78,204 on catering.

The hotel has on an almost daily basis drawn visits from foreign officials. This week it was Imran Ismail, the governor of a Pakistani province who was in Washington to meet with the State Department and members of Congress to discuss human rights issues in Kashmir, among other topics. The visit was first noticed by Zach Everson, who runs the 1100 Pennsylvania newsletter.

Jose Manuel del Gallego Romualdez, the Philippine ambassador to the United States, explained his own reasoning for scheduling an event at the hotel last year.

“The Trump hotel may have some political undertones because it is associated with the U.S. president,” Mr. Romualdez wrote in a column in a Philippine newspaper. “But since several other embassies have also held their national day celebrations at the Trump hotel, which were well attended — I decided — why not do it there, too.”