Democrats on the Senate Health, Education, Labor and Pensions Committee are demanding information from Health and Human Services Secretary Tom Price about his use of private planes for official government travel.

"This decision is particularly shocking as you serve in an administration that routinely calls for draconian spending cuts and a reduction in government waste, and you yourself have repeatedly advocated for fiscal restraint," Democrats on the HELP Committee wrote in a letter to Price. "It is therefore especially difficult to understand the use of taxpayer funds for your luxury travel."

Since May, Price has chartered private jets for at least two dozen flights, costing taxpayers more than $400,000. The Department of Health and Human Services said Price began taking private planes after he was forced to cancel an event in April because weather delayed a commercial flight.

Price combined official and personal business on at least two of the trips where he flew on a private plane.

Democrats on the Senate HELP Committee asked Price to turn over documents related to each flight for which he used a private jet, and detail how much each flight cost. The committee members also requested all communications with the White House regarding Price's travel, since White House press secretary Sarah Sanders told reporters the secretary's travel "wasn't approved" by the White House.

"The administration's priorities could not be clearer," the HELP Democrats wrote. "Administration officials travel to resorts and nearby cities on private planes while patients and families worry about access to the healthcare programs they rely on to survive."

Price's travel on private planes has led to heightened scrutiny of how Trump administration officials are spending money.

The House Oversight and Government Reform Committee said Wednesday it opened an investigation into Price's use of private jets.

President Trump said he is "not happy" about Price's use of private jets and is "looking into it."