Rep. Adam Schiff (D-Calif.) mocked Tom Price on Friday, saying the former Health and Human Services secretary committed "the one unpardonable sin" in President Trump's world before his resignation.

"Tom Price committed the one unpardonable sin in Trump's world: Being rich, but not rich enough to own his own private jet," Schiff tweeted.

Schiff was responding in a tweet to remarks Trump gave to reporters before it was announced that Price had resigned.

"We have great secretaries, and we have some that actually own their own planes," Trump said. "That solves that."

Price resigned Friday after criticism over his use of private jets for official business trips.

The former Health secretary took multiple government planes and private jets at a cost of more than $1 million since May, according to Politico.

Price apologized on Thursday and said he would repay just under $52,000 for his "seats" on the flights, but Trump said Friday he was "not happy" and didn't like the "optics" of Price's flights. The White House later released a copy of Price's resignation letter that Trump accepted.

At the time of his nomination to the HHS post in January, Price had a net worth of at least $8.2 million, which included more than one bank account containing at least $100,000 in cash, according to his personal financial disclosure forms.

Interior Secretary Ryan Zinke and Environmental Protection Agency chief Scott Pruitt have also come under scrutiny in recent days for their use of private aircraft for government business.