WASHINGTON (Reuters) - U.S. Health and Human Services Secretary Tom Price promised on Thursday to repay the nearly $52,000 cost of his seats on private charter flights, as expensive air travel by Trump administration officials drew sharp scrutiny from Congress.

“Today, I will write a personal check to the U.S. Treasury for the expenses of my travel on private charter planes,” said Price, a former member of Congress, in a statement. “The taxpayers won’t pay a dime for my seat on those planes.”

Price was one of a handful of senior officials in President Donald Trump’s administration put on the defensive over reports about their use of charter flights and government aircraft, sometimes for personal travel, when they could have flown commercial for less money.

Price told Fox News on Thursday that Trump had spoken to him about the matter and was not happy. Asked if he retained Trump’s confidence, Price said he worked at the president’s pleasure.

Washington media outlet Politico reported that Price had taken at least two dozen private charter flights since May at a cost to U.S. taxpayers of more than $400,000.

Politico in a report on Thursday night said the White House had approved the use of military aircraft for other trips by Price to Africa, Europe and Asia in the spring and summer that cost taxpayers more than $500,000.

“Secretary Price will write a personal check to the U.S. Treasury for $51,887.31,” a spokeswoman for the Department of Health and Human Services said on Thursday.

Price is paying his individual share of the charter flight cost, an HHS official said. Price said earlier on Thursday he believed he retained Trump’s confidence.

Senior U.S. government officials travel frequently, but are generally expected to keep the costs down by taking commercial flights or the train when possible.

Health and Human Services (HHS) Secretary Tom Price speaks at a news conference on annual influenza prevention at the Press Club in Washington, U.S., September 28, 2017. REUTERS/Kevin Lamarque

Price, Environmental Protection Agency Administrator Scott Pruitt and Treasury Secretary Steve Mnuchin were all in the spotlight for their travel habits.

Politico reported late on Thursday that Interior Secretary Ryan Zinke took a charter flight from Las Vegas to Glacier Park International Airport in Montana in June that cost $12,375. The route is served by commercial flights.

Zinke also took charter flights between St. Croix and St. Thomas in the U.S. Virgin Islands in March and used a military aircraft to travel to Norway in May, according to Politico.

“As with previous interior secretaries, the Secretary traveled on charter flights when there were no commercial options available,” Interior Department spokeswoman Heather Swift said in a statement. “All travel is pre-approved by the ethics office before booking and the charter flights went through an additional level of due diligence.”

Republican Senator Chuck Grassley urged Trump in a statement “to emphasize to cabinet secretaries the necessity of using reasonable and cost-effective modes of travel in accordance with federal restrictions.”

PRICES EXPRESSES REGRET

In his statement, Price said his travel had been approved by legal and departmental officials. But he expressed regret over the concerns raised and pledged to take no more private charter flights while health secretary.

“I was not sensitive enough to my concern for the taxpayer,” said Price, an orthopedic surgeon. He was confirmed in February as health secretary despite questions about how he had been buying shares in publicly traded healthcare companies while working on legislation affecting them.

As a conservative Republican U.S. representative in 2009, Price chastised “the fiscal irresponsibility” of private-plane use by government officials in an appearance on CNBC television that he also posted on Twitter.

Price’s travels and those of the entire Trump Cabinet are being probed by a U.S. House of Representatives committee. Senate Democrats wrote to Price on Thursday demanding information about his flights.

The inspectors general at HHS, EPA and Treasury are investigating to see if government travel rules were followed.

The EPA’s inspector general said last month it was investigating Pruitt’s frequent travels to his home state of Oklahoma. The Washington Post reported on Thursday that Pruitt had taken at least four noncommercial and military flights since mid-February, costing taxpayers more than $58,000.

EPA spokeswoman Liz Bowman said Pruitt did use one charter flight but that other commissioned flights were done on government planes.

“The administrator flies commercial, unless there is a necessity to do otherwise, and with approvals from EPA’s ethics office,” said EPA spokesman Jahan Wilcox.

At the Treasury Department, the inspector general is reviewing Mnuchin’s use of a government plane to fly to Kentucky in August for a visit to Louisville and Fort Knox. Mnuchin and his wife viewed the solar eclipse during the trip.

On the “CBS This Morning” program on Thursday, Mnuchin said he would use military planes in the future only when there are national security issues or “there’s no other means” of travel.