WASHINGTON—President Donald Trump on Wednesday said he had ousted his Veterans Affairs secretary, David Shulkin, and tapped the White House physician, Ronny Jackson, as his replacement.

“I am pleased to announce that I intend to nominate highly respected Admiral Ronny L. Jackson, MD, as the new Secretary of Veterans Affairs,” Mr. Trump tweeted Wednesday. He said Robert Wilkie, who currently serves as under secretary of defense for personnel and readiness at the Department of Defense, would serve as acting secretary “in the interim.”

In a statement issued by the White House, Mr. Trump praised Dr. Shulkin’s work and “the many great things we did together at Veterans Affairs, including the VA Accountability Act that he was helpful in getting passed.” The president called Dr. Shulkin a “great supporter of veterans across the country and I am grateful for his service.”

Dr. Shulkin didn’t return a request for comment on Wednesday.

Dr. Jackson is a U.S. Navy rear admiral who has served as a White House physician during the past three administrations. In that role, he has overseen health care for the cabinet and senior staff, served as a physician supervisor at Camp David and led the White House Medical Unit, the White House said.