NEW YORK/WASHINGTON (Reuters) – A Democratic U.S. congressman is asking the Energy Department’s watchdog to investigate Energy Secretary Rick Perry’s travel on chartered aircraft, the congressman said at a hearing on Capitol Hill on Thursday.

U.S. Representative Frank Pallone said Perry’s trips on chartered planes need scrutiny in light of the “extreme” budget cuts the department faces in a 2018 federal budget proposed by President Donald Trump.

Perry said in his opening statement in the hearing, being held by the House of Represenatives’ Energy and Commerce Subcommittee on Energy, that as a former Texas governor he understood the issue of travel oversight and the need to spend money on travel appropriately and thoughtfully.

“I travel a lot to do my job. I do it in a way that I think is thoughtful,” he said.

Perry’s charter flights have cost taxpayers more than $56,000, according to records the Energy Department released to Reuters on Friday. One of those flights – from a coal mine in Pennsylvania to a nuclear facility in Ohio – occurred just a day before former U.S. Health and Human Services Secretary Tom Price resigned and promised to repay the government for some $52,000 worth of travel including private flights.

Perry said on Thursday it would have been “very difficult” to take a commercial flight from the Pennsylvania site to the Ohio plant.

Pallone is asking the Energy Department’s Office of Inspector General to open an investigation, his spokesman wrote in an email to Reuters.

Officials in the inspector general’s office did not immediately respond to a request for comment.

Inspectors general for the U.S. Environmental Protection Agency and the U.S. Interior Department have opened similar investigations into charter travel by those agencies’ heads, EPA Administrator Scott Pruitt and Interior Secretary Ryan Zinke.