(NewsNation) — Defense Secretary Lloyd Austin was diagnosed with and treated for prostate cancer, a statement from officials at Walter Reed National Military Medical Center said Tuesday.

Austin, the statement said, was admitted to Walter Reed National Military Medical Center on Dec. 22, 2023, where he underwent a “minimally invasive” surgical procedure to treat and cure prostate cancer.

He returned home the next morning, according to the statement. The cancer was detected early, and his prognosis is “excellent,” officials said. However, on Jan. 1, Austin was again admitted to the hospital after complications from the procedure in December, including nausea as well as severe abdominal, hip and leg pain. An initial evaluation showed he had a urinary tract infection, the statement said.

Then, on Jan.2, he was transferred to the intensive care unit.

The infection has since cleared, the statement said, and Austin continues to make progress.

During this second stay, Austin never lost consciousness and never underwent general anesthesia, Walter Reed officials said.

Maj. Gen. Pat Ryder, the Pentagon press secretary, said at a news conference Tuesday afternoon that Austin is still in the hospital.

Questions remain about why President Joe Biden and other top officials weren’t informed for days that Defense Secretary Lloyd Austin had been hospitalized. The White House was not told he was in the hospital until Jan. 4., and it was only Tuesday morning that Biden learned about Austin’s prostate cancer diagnosis, NSC spokesperson John Kirby said.

A Pentagon spokesman pointed to one reason: A key staffer was out sick with the flu.

When asked about why it took so long for the public to be notified about Austin’s condition, Ryder said, “despite the frequency of prostate cancer, discussions about screening, treatment and support are often deeply personal and private ones.”

Some Republicans have demanded Austin’s resignation, but the Pentagon said he has no plans to step down.

White House officials on Monday emphasized that Austin retains Biden’s confidence. White House press secretary Karine Jean-Pierre said Biden appreciated Austin’s statement on Saturday, in which he took responsibility for the lack of transparency.

Officials initially gave few details on what the Pentagon press secretary called an “elective procedure,” but one serious enough that Austin temporarily transferred some of his authorities to his deputy. Ryder said the decision to say the procedure was elective had been developed in consultation with Austin’s doctors.

Austin also transferred some of his authority to Deputy Defense Secretary Kathleen Hicks after being taken back to Walter Reed National Military Medical Center on Jan. 1.

Austin, who resumed his duties on Jan. 5, is no longer in intensive care.

The Associated Press contributed to this report.

This story is developing. Refresh for updates.