WASHINGTON – Fighting to keep his job, Health and Human Services Secretary Tom Price said Thursday that he will write a personal check to reimburse taxpayers for the cost of his travel on charter flights taken on government business and pledged to fly commercial in the future – “no exceptions.”

“I regret the concerns this has raised regarding the use of taxpayer dollars,” Price said in a statement. “I was not sensitive enough to my concern for the taxpayer.” His mea culpa came a day after a public rebuke from President Trump.

Former Health and Human Services Secretary Tom Price said Tuesday that the Republican tax bill would drive the cost of health insurance higher for some because it repeals the Affordable Care Act's individual mandate. Associated Press/ Manuel Balce Ceneta

The repayment – $51,887.31, according to Price’s office – was for the embattled secretary. Price did not address the overall cost of the flights, which could amount to several hundred thousand dollars.

Price, a former congressman from Georgia regarded as a conservative policy expert, said he hopes to keep his job. At the White House, press secretary Sarah Huckabee Sanders wouldn’t go that far.

“We’re going to conduct a full review and we’ll see what happens,” Sanders told reporters. Travel by other Cabinet secretaries is also attracting scrutiny.

Price said all his travel was legally approved by the department he heads.

On Wednesday Trump declared that he’s “not happy” with his Health and Human Services secretary over reports that Price flew on costly charters when he could have taken cheaper commercial flights on government business. Asked whether he’d fire Price, Trump said, “We’ll see.”

Price told reporters Thursday, “I think we’ve still got the confidence of the president.” About the controversy, he said, “We’re going to work through this.”

In his statement, Price said taxpayers “won’t pay a dime for my seat on those planes.”

Price played a supporting role in the fruitless Republican effort to repeal Barack Obama’s health care law – another source of frustration for the president.

Prompted partly by controversy over Price, the House Oversight and Government Reform Committee has launched a wide-ranging investigation into travel by Trump’s political appointees. On Wednesday the committee sent requests for detailed travel records to the White House and 24 departments and agencies, dating back to the president’s first day in office.

Travel by Treasury Secretary Steven Mnuchin and EPA Administrator Scott Pruitt has also drawn criticism.

A senior Republican lawmaker on Thursday urged Trump to lay down the rules. “Considering the many travel options to and from Washington, D.C., I’m urging you to emphasize to cabinet secretaries the necessity of using reasonable and cost-effective modes of travel in accordance with federal restrictions,” Sen. Chuck Grassley, R-Iowa, wrote to Trump.

The president vented his displeasure with Price to reporters on Wednesday as he left the White House for a trip to sell his tax overhaul in Indianapolis.

“I was looking into it, and I will look into it, and I will tell you personally I’m not happy about it,” Trump responded when asked about Price’s travel. “I am not happy about it. I’m going to look at it. I’m not happy about it and I let him know it.”

Price’s travels were first reported last week by Politico, which said it had identified a couple dozen charter flights. Cheaper commercial flights were a viable option in many cases.

On a June trip to Nashville, Price also had lunch with his son, who lives in that city, according to Politico. Another trip was from Dulles International Airport in the Washington suburbs to Philadelphia International Airport, a distance of 135 miles.

Last Friday the HHS inspector general’s office announced it was conducting a review to see if Price complied with federal travel regulations, which generally require officials to minimize costs.

Price’s office had initially said the secretary’s demanding schedule sometimes did not permit the use of commercial airline flights.

Trump’s publicly expressed displeasure – or ambivalence – has been a sign in the past that the tenure of a key aide will soon be over.

In August, the president was asked if he still had confidence in Steve Bannon, then a senior strategist in the White House. “He’s a good person. He actually gets very unfair press in that regard. But we’ll see what happens with Mr. Bannon,” Trump said. Bannon was out three days later.

Price, an ally of House Speaker Paul Ryan, is a past chairman of the House Budget Committee, where he was a frequent critic of wasteful spending. As HHS secretary, he has questioned whether the Medicaid health insurance program for low-income people delivers results that are worth the billions of dollars taxpayers spend for the coverage. He’s a former orthopedic surgeon who once practiced in an inner-city hospital.