Veterans Affairs Secretary Robert Wilkie testifies before the House Appropriations subcommittee on Capitol Hill in Washington, Tuesday, Feb. 26, 2019. Credit: Jose Luis Magana | AP

Veterans Affairs Secretary Robert Wilkie, whose career has long gravitated to military matters, has promoted himself to the White House to be President Trump’s next secretary of defense, according to people familiar with his efforts.

His internal campaign comes as Trump has yet to formally nominate a candidate to replace Jim Mattis, the retired Marine general who quit last December over differences with the president. Mattis’s deputy, former Boeing executive Patrick Shanahan, has been auditioning for the role as acting secretary since early January.

Shanahan is widely expected at the Pentagon to be nominated as permanent secretary, but officials have said there’s no certainty about his elevation until a White House announcement. The president has been known to change his mind on personnel decisions.

Shanahan’s limited foreign policy experience, particularly with the wars in Iraq and Afghanistan, has prompted some uneasiness on Capitol Hill. A few Senate Republicans have openly criticized his unwavering loyalty to the president, particularly on Trump’s controversial announcement that he was withdrawing troops from Syria, and questioned whether he could disagree with Trump in private when appropriate. He did not serve in the military.

Wilkie is in only his eighth month leading Veterans Affairs, which he took over following a tour as undersecretary of defense for personnel and readiness at the Pentagon. He has pitched himself to top White House officials as an experienced hand in defense policy and running large bureaucracies, according to an administration official and another person close to the administration who requested anonymity to discuss personnel matters.

Wilkie, 56, often says he was born in “khaki diapers.” He is a former Navy reservist and lieutenant colonel in the Air Force reserve and son of a soldier severely wounded during the Vietnam War. His career has taken him from Senate staffer to the National Security Council and the Pentagon, where he was assistant secretary of defense for legislative affairs from 2006 to 2009.

It’s unclear whether Trump has considered him as a serious candidate for defense secretary, although the president is said to hold him in high regard.

VA spokesman Curt Cashour said in an email that Wilkie “remains 100 percent focused on his job as VA secretary.”

“He is proud to serve the Veterans of this country and is honored to be a part of the record pace of reform at the department under President Trump’s leadership,” Cashour wrote.

Wilkie is still working to restore morale at the second-largest federal agency after a long period of turmoil under Trump, when a gap in leadership and political infighting led to an exodus of top career staff. Veterans will continue to be a key constituency for the president as he seeks reelection, and VA is one of the few corners of the government where the proposed budget the White House released Monday included a spending increase.

Wilkie is tackling major challenges for veterans as he balances an administration priority to increase veterans’ access to private doctors outside VA. Democratic lawmakers have criticized him for a lack of transparency in the process. Wilkie also is overseeing an expensive overhaul to VA’s antiquated medical-records system and an expansion in assistance provided to caregivers for military families.

His staff stumbled last fall when computer problems resulted in delayed or miscalculated housing allowances to veterans returning from Iraq and Afghanistan under the Forever GI Bill. But his reviews overall have been largely positive.

“I think he’s a very qualified man,” said Sen. Johnny Isakson, R-Ga., chairman of the Senate Veterans’ Affairs Committee. “I would hate for us to lose him under any circumstance.”

The committee’s top Democrat, Sen. Jon Tester of Montana, was more blunt, saying that Wilkie’s departure would return VA to a state of turmoil.

“That’s a problem because you need continuity within the VA,” Tester said. He said he understood why Wilkie might be attracted to the defense position, but “we make a commitment to our veterans, and that VA secretary is an important position. If we don’t have a good person there, good things don’t happen to our vets. I get it, but I’m very concerned if that’s the case.”

Shanahan is scheduled to give his first congressional testimony as acting secretary this week, when he is sure to face tough questions about Trump’s defense policies. The appearance promises to be a key test for an official whose career has been spent in aviation rather than foreign policy and who would become one of the administration’s most visible Cabinet members.

The Washington Post’s Missy Ryan and Paul Sonne contributed to this story.