President Trump on Wednesday fired David Shulkin, the embattled head of the Department of Veterans Affairs, the latest high-profile ouster to roil the White House.

In a tweet, the president named Dr. Ronny L. Jackson, the chief White House physician, as the next VA secretary. Until Jackson can be confirmed, the acting head of the agency will be Robert Wilkie, the undersecretary for personnel at the Defense Department, Trump tweeted.

Shulkin has been besieged by allegations of ethical lapses coupled with a determined campaign against him by conservatives who favor greater privatization of the huge VA healthcare system.

Over the weekend, Christopher Ruddy, the chief executive of Newsmax, a conservative news site, who is a friend of Trump’s, said in television interviews that he had talked to the president and that Shulkin was “likely to depart the Cabinet very soon.”