Secretary of Defense Lloyd Austin is not resigning, the Pentagon said, amid his unannounced, multi-day hospital stay that was not initially disclosed even to President Biden.

Department of Defense press secretary Major General Pat Ryder told Fox News Digital that Austin doesn't have any plans to leave his post.

"Secretary Austin has no plans to resign," Ryder said. "He remains focused on conducting his duties as Secretary of Defense in defense of our nation."

The comment came in response to former President Trump, who had called for Austin to lose his job.

The Pentagon did not disclose Austin's hospital stay, which started on New Year's Day, earning rebukes from lawmakers and the press.

SECRETARY OF DEFENSE LLOYD AUSTIN REMAINS HOSPITALIZED AFTER MYSTERY PROCEDURE; DOD REMAINS MUM ON RELEASE

"Failed Secretary of Defense Lloyd Austin should be fired immediately for improper professional conduct and dereliction of duty," Trump wrote on Sunday on TruthSocial.

"He has been missing for one week, and nobody, including his boss, Crooked Joe Biden, had a clue as to where he was, or might be," the former president continued.

"He has performed poorly, and should have been dismissed long ago, along with ‘General’ Mark Milley, for many reasons, but in particular the catastrophic surrender in Afghanistan, perhaps the most embarrassing moment in the history of our Country!" Trump wrote.

The Pentagon has said little about Austin's unannounced hospital stay and has not said when the secretary of defense will be released from medical care.

Additionally, the five-walled citadel refuses to say why Austin was hospitalized to begin with.

Austin was admitted to Walter Reed National Military Medical Center last Monday, for what Ryder described as complications from an elective medical procedure.

Austin and Biden authorized the Jan 4th strike in Baghdad before Austin was hospitalized. "The Secretary was aware of the strike/actions on January 4," a senior U.S. defense official said.

On Sunday, Ryder told Fox News that Austin had an elective medical procedure at Walter Reed on December 22, 2023. Austin was on leave at the time of the procedure, and he returned home the next day.

However, the defense secretary started to experience "severe pain" on January 1 and was admitted to the intensive care unit (ICU) at Walter Reed Hospital.

Ryder said Austin was placed in the ICU to ensure immediate access to his medical needs, but he remained there, in part, because of privacy and hospital space considerations.

Ryder told Fox News he could not provide additional information about Austin’s ailments for privacy reasons. Austin resumed his duties from the hospital on Friday.

Fox News Digital's Greg Wehner and Liz Friden contributed reporting.