Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Fired Veterans Affairs Secretary David Shulkin said he believes that Trump administration political appointees sent to the department were working to undermine him.

Shulkin also said on MSNBC's "All In with Chris Hayes" Thursday that he spoke to President Donald Trump by phone on Wednesday, the same day the president announced on Twitter that Shulkin would be replaced with the White House physician, Adm. Ronny Jackson.

Trump gave no indication during Wednesday’s call that he would be fired, Shulkin said. "Chief of staff Kelly gave me a call, which I appreciated, he gave me a heads-up," Shulkin said, "but that was much after the phone call."

Shulkin said that during the phone call Trump was "very focused, he was very inquisitive about the things that we were working on, making sure that we were focused on the job at hand."

The interview follows an op-ed Shulkin wrote for The New York Times that was published online Wednesday in which he said that "the advocates within the administration for privatizing V.A. health services" reject debate and that "they saw me as an obstacle to privatization who had to be removed."

He said in the Times that "I am convinced that privatization is a political issue aimed at rewarding select people and companies with profits, even if it undermines care for veterans."

In another interview, on Friday morning with MSNBC's "Morning Joe," Shulkin said he remained "very concerned about the future of the VA ... and that it's not hijacked and dismantled."

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Shulkin told MSNBC the night before that Trump has the clear authority to decide who he wants to head the agency.

"There was clear evidence, though, that the political appointees inside the VA were working against me and my leadership team because they felt that we were trying to strengthen the VA rather than moving towards privatization," Shulkin said, declining to state names.

Shulkin said he saw no evidence that efforts to block him were directed by Trump.

"I think that the president wants to improve care for veterans," Shulkin said. "I think that he is not served well by political appointees who are taking their own personal agendas much further than I think that he intended them to."

Shulkin, who served as undersecretary in charge of the veterans’ health system during the Obama administration, clashed with Trump political appointees who surrounded him at the VA.

Some of the tension arose from a central policy dispute: The Trump appointees, both within the VA and at the White House, reportedly want to see the VA transition to subsidizing private health care for veterans, while Shulkin resisted those efforts.

"I think that this is a very complex organization, and from the outside it seems easy — why aren’t things fixed faster," Shulkin said on MSNBC Thursday. "The truth is that the VA has had systemic problems for decades, which spans multiple administrations."

A VA inspector general's report in February found that taxpayers had picked up the tab for Shulkin’s wife when she accompanied him on a European business trip.

Shulkin said Thursday that he did nothing wrong, and that the IG found that staff made mistakes, that he had no knowledge of it and that after he was informed he paid back all of the funds in question.

The report said that Shulkin’s chief of staff doctored emails to justify his wife traveling to Europe. Shulkin said the chief of staff chose to retire after the report. “If you change records, of course that’s wrong,” Shulkin said. "But the inspector general report also said very clearly that I wasn’t involved."

The former Veterans Affair secretary said he is willing to provide any assistance he can to Jackson, his replacement, but said Jackson will need a solid team to surround him if he wants to succeed.

"I don’t think anybody is necessarily prepared for a job this big," he told "Morning Joe."

The removal of Shulkin comes amid a spate of firings or other dismissals in the Trump administration, including the departures of Secretary of State Rex Tillerson and national security adviser H.R. McMaster.

Shulkin was confirmed by the Senate in 2017 by a vote of 100-0.

The Veterans of Foreign Wars in a statement on Thursday praised Shulkin and was critical of Trump’s choice to replace him with Jackson.

“Dr. Jackson’s bio does not reflect any experience working with the VA or with veterans, or managing any organization of size, much less one as multifaceted as the Department of Veterans Affairs, so the VFW will be closely monitoring his Senate confirmation process,” the veterans group said.

But the VFW noted that Jackson served in Iraq as an emergency physician and recognized his service.

“We look forward to working with him and his staff to continue building upon the progress created by his predecessors, progress that properly takes care of America’s wounded, ill and injured veterans first,” VFW National Commander Keith Harman said.