US President Joe Biden did not learn that his defense secretary, Lloyd Austin, had prostate cancer until Tuesday, the White House said, minutes after it was disclosed to the public along with an infection that was also kept under wraps.

Austin, who is 70, has been hospitalised since January 1 at Walter Reed National Military Medical Center — a fact that the Pentagon had kept from the public, the White House and Congress for much of last week, triggering a major political backlash.

Austin’s own deputy, Kathleen Hicks, was also kept in the dark for days, even after she was told during a vacation in Puerto Rico to assume some of his duties on January 2.

“He (Biden) was not informed until last (Thursday) that Secretary Austin was in the hospital. He was not informed until this morning that the root cause of that hospitalisation was prostate cancer,” White House spokesperson John Kirby said.

“Nobody at the White House knew that Secretary Austin had prostate cancer until this morning, and the President was informed immediately after.”

Austin and Biden spoke on Saturday and it was unclear why Biden did not learn until Tuesday about Austin’s prostate cancer.

Republicans seized on the incident as evidence of dereliction of duty by Austin, a retired four-star general who led forces in Iraq and is America’s first Black defense secretary. The Republican who leads the House Armed Services Committee launched a formal inquiry.

“With wars in Ukraine and Israel, the idea that the White House and even your own Deputy did not understand the nature of your condition is patently unacceptable,” Representative Mike Rogers wrote in a letter to Austin on Tuesday.

Austin was taken by ambulance on January 1 to Walter Reed after suffering complications from his Decemebr 22 prostate cancer treatment, including nausea with severe abdominal, hip, and leg pain. After he was diagnosed with a urinary tract infection, Austin was moved on Jan. 2 to an intensive care unit.

“Further evaluation revealed abdominal fluid collections impairing the function of his small intestines. This resulted in the backup of his intestinal contents which was treated by placing a tube through his nose to drain his stomach,” the hospital said.

Austin’s prostate cancer treatment on December 22 required Austin go under general anesthesia, but he has retained consciousness during his latest visit, according to a statement from Walter Reed.

Walter Reed gave an upbeat outlook for Austin but cautioned that his recovery could take time. “His infection has cleared. He continues to make progress and we anticipate a full recovery although this can be a slow process,” it said in a statement.