Updated at 5:33 p.m. | Health and Human Services Secretary Tom Price resigned Friday afternoon amid a scandal stemming from his use of taxpayer funds for private charter flights, according to the White House press secretary.

Price reportedly spent as much as $400,000 of taxpayer monies on chartered flights, including one to the tune of $25,000 to fly between Washington and Philadelphia.

In his resignation letter, emailed late Friday afternoon by the White House, Price praised Trump, writing that “under your leadership, the department is working aggressively to improve the health and well-being of all Americans.” He alluded to a still-incomplete effort to pass a health care overhaul law that Price wrote would “reform a broken heath care system’ and “empower patients.”

But Price wrote that he opted to step down because “recent events have created a distraction from these important objectives,” telling Trump the move is necessary “in order for you to move forward without further disruption.”

Don J. Wright will serve as acting secretary effective at 11:59 p.m. Friday. 

Trump let his frustration with Price show publicly in recent days.

“He’s a very fine man. I certainly don’t like the optics,” Trump told reporters Friday as he left the White House for another weekend at his Bedminster, N.J., resort. “I’m not happy, I can tell you that. I’m not happy.”

Trump selected Price for the job in large part to help design a plan that would repeal and replace Barack Obama’s 2010 health care law. Price had been the House Budget Committee chairman, viewed by the president as just the kind of individual that could negotiate with House and Senate Republicans to achieve that major campaign promise.

Price, however, did not deliver a bill to the president for his signature.

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A tipping point for Trump could have come when even congressional Republicans criticized Price’s actions.

The GOP-controlled House Committee on Oversight and Government Reform announced earlier this week it would open an investigation of Trump administration air travel practices after the Price flights went public.

That panel’s GOP chairman, Rep. Trey Gowdy of South Carolina, and ranking Democrat, Elijah Cummings of Maryland, sent a letter Tuesday to White House chief of staff John Kelly demanding reams of information for its probe.

Trump directed a review of all HHS private charter jet usage, and the department’s inspector general is conducting its own probe of the Price matter.

The HHS chief announced Thursday he would “write a personal check to the U.S. Treasury for the expenses of my travel on private charter planes,” adding that he “would no longer take private charter flights as the secretary of HHS no exceptions.”

Price is the latest in a growing list of senior Trump administration officials to leave during the president’s first nine months in office.

Already gone are retired Lt. Gen. Michael Flynn (Trump’s first national security adviser); Sean Spicer (former press secretary); Reince Priebus (former White House chief of staff); Anthony Scaramucci (the onetime incoming communications director); Steve Bannon (Trump’s former chief strategist); James Comey (the fired FBI director); and Sally Yates (the fired acting attorney general).

Price’s departure is particularly complicated because much of the HHS leadership ranks have remained vacant. Trump’s nominee to be deputy secretary, Eric Hargan, was reported out of the Finance Committee in June, but has yet to be confirmed.