President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE said Wednesday he is removing Veterans Affairs (VA) Secretary David Shulkin David Jonathon ShulkinVA inspector general says former top official steered M contract to friend Schumer demands answers in use of unproven coronavirus drug on veterans Former Trump VA secretary says staffer found plans to replace him in department copier MORE and tapping White House physician Adm. Ronny Jackson as his replacement, ending weeks of uncertainty at the embattled agency.

Trump announced the decision on Twitter, a move that caps off a stunning fall for Shulkin, who had once been among Trump’s favorite Cabinet secretaries.

“I am pleased to announce that I intend to nominate highly respected Admiral Ronny L. Jackson, MD, as the new Secretary of Veterans Affairs,” Trump tweeted.

The president thanked Shulkin for “service to our country and to our GREAT VETERANS” and said that Robert Wilkie, the under secretary of defense for personnel and readiness, would serve as interim VA secretary until Jackson is confirmed.

....In the interim, Hon. Robert Wilkie of DOD will serve as Acting Secretary. I am thankful for Dr. David Shulkin’s service to our country and to our GREAT VETERANS!

"Congrats to Admiral Ronny Jackson, MD. Thank you Dr. David Shulkin for your dedication and service to helping our veterans," Vice President Pence tweeted

Jackson has served as the presidential physician since 2013, when former President Obama was in office. His experience in the White House goes back to the George W. Bush administration and he was also in charge of resuscitative medicine for a trauma-response unit during the Iraq War.

The doctor gained national attention in January when he gave an hourlong press conference praising Trump’s health and crediting his "good genes."

Trump said Jackson, who has no experience running a large organization, "is highly trained and qualified" and as a service member himself "has seen firsthand the tremendous sacrifice our veterans make."

Shulkin’s ouster adds to the shake-up in the Trump administration that has already resulted in the departures of Trump's secretary of State, top economic aide and his second national security adviser.

The only Cabinet holdover from the Obama administration, Shulkin had been in the hot seat for months over a scathing report accusing him of misusing taxpayer dollars.

But a White House spokesman said as recently as Monday that Trump retained confidence in the secretary, responding to reports that the president was telling associates that Shulkin was on the way out.

The moderate former hospital executive initially appeared to be the least controversial of Trump’s Cabinet members.

Shulkin was confirmed unanimously and appeared frequently in the White House briefing room during Trump’s first year to tout accomplishments, including legislation that makes it easier for the 360,000-person agency to fire bad employees.

Trump remarked in June that he’d “never have to use” his reality show catchphrase, “You’re fired,” on Shulkin.

“I appreciate the work of Dr. David Shulkin and the many great things we did together at Veterans Affairs, including the VA Accountability Act that he was helpful in getting passed,” Trump said in a prepared statement Wednesday. “He has been a great supporter of veterans across the country and I am grateful for his service.”

Feelings on Shulkin began to sour in February, when the VA’s inspector general released a report on a trip to Europe over the summer that found Shulkin spent most of his time sightseeing rather than conducting official business and improperly accepted tickets to a Wimbledon tennis match as a gift.

It also said a top aide, who has since resigned, altered an email to gain approval to use taxpayer money to pay for Shulkin’s wife to accompany him on the trip.

After the report’s release, Shulkin said he would reimburse the government for his wife’s travel and the Wimbledon tickets.

But he also went on a media blitz blaming the report on an internal rebellion by some Trump appointees. The interviews led long-bubbling tensions to break into the open, with reports surfacing that two senior VA officials tried to oust Shulkin late last year.

More bad news for Shulkin has since piled up, including reports of another inspector general investigation into an allegation that Shulkin asked a member of his security detail to accompany him to a Home Depot and carry furniture items into his home.

Some Trump political appointees seized the opportunity to try and force Shulkin out over policy disagreements.

Top Republicans in Congress, including the chairmen of the House and Senate Veterans Affairs committees, had stuck by Shulkin, as did leading veterans organizations. Supporters said Shulkin had done a good job reforming a department that has been plagued by scandal.

“Dr. Shulkin has made a tremendous impact toward improving the lives of veterans during his time at the U.S. Department of Veterans Affairs," Isakson said. "He has been instrumental in all that we have accomplished in the last year, and I thank Dr. Shulkin for his dedicated service to our country and our veterans. I look forward to meeting Admiral Jackson and learning more about him.”

Democrats and veterans organizations also looked at Shulkin as the bulwark against privatization of the VA.

At the heart of the dispute between Shulkin and Trump appointees were changes to a program known as Choice that allows some veterans to seek private health care. Shulkin favored a modest expansion of the program that would still leave it up to VA doctors whether patients can seek private care.

Shulkin’s opponents, though, say that approach is out of step with sweeping reforms Trump promised during his presidential campaign. They want a more aggressive change to the Choice program that critics say would amount to privatization of the VA.

The agency has been under fire since 2014, when it was revealed that some veterans waited months for doctor appointments at the Phoenix VA. Some officials created secret records to cover up the long delays.

Updated at 6:38 p.m.