Pentagon orders 30-day review of notification process over Secretary of Defense's hospitalization

The Pentagon Monday night ordered a 30-day review of how the notification process over Secretary of Defense Lloyd Austin's hospitalization was botched.

In announcing the review Kelly Magsamen, Austin’s chief of staff, also announced immediate changes to make sure that senior leaders at the Pentagon and the White House are quickly notified whenever the secretary has a transfer of authority to the Deputy Secretary of Defense.

President Joe Biden was exasperated at not more quickly being informed of Defense Secretary Lloyd Austin's ongoing hospitalization -- which was only publicly revealed late last week after several days -- a U.S. official tells ABC News as the Pentagon is providing some new details about Austin's health issues.

The White House is publicly standing by Austin, with one administration official telling ABC News on Sunday that Biden "has full confidence in Secretary Austin" and is "looking forward to him being back at the Pentagon."

The president and Austin also spoke Saturday evening and had what the White House official called a "warm conversation."

However, the U.S. official said White House aides were angered at the lack of information about Austin being hospitalized at Walter Reed National Military Medical Center in Bethesda, Maryland. (The White House did not have further comment for this story.)

The frustration comes as another U.S. official confirmed to ABC News on Saturday that the White House did not learn about Austin's hospitalization until Thursday night -- three days after he was hospitalized on the night of New Year's Day for complications resulting from what was characterized as "a minor, elective procedure."

Congress was first notified of Austin's hospitalization on Friday afternoon, shortly before it was made public in a Pentagon news release, ABC News reported on Saturday.

The timeline of information being shared about the health problems of the country's top defense official, who is 70 years old, has raised questions inside and outside of the government.

Later on Sunday, a Pentagon spokesperson, for the first time, provided day-by-day details of how Austin came to be in intensive care at Walter Reed.

In a statement initially provided exclusively to ABC News, Maj. Gen. Pat Ryder said that Austin had his elective procedure on Dec. 22 and then went home the next day.

On Jan. 1, "he began experiencing severe pain and was transported" back to Walter Reed, Ryder said.

"For privacy reasons, we're not able to provide additional information. He was placed in the hospital's intensive care unit to ensure immediate access ... due to his medical needs, but then remained in that location in part due to hospital space considerations and privacy," Ryder said.

Kathleen Hicks, Austin's deputy, was not informed in advance and was on vacation in Puerto Rico when he was hospitalized, according to the U.S. official who also described Biden's exasperation.

She had to be taken to a secure location to help fill in for her boss, this official said

Austin "is recovering well and in good spirits," Ryder said in another statement on Sunday, adding that officials "do not have a specific date for his release at this time." The secretary resumed his duties on Friday night.

While the White House was in the dark for days, according to officials, Gen. CQ Brown Jr., the chairman of the Joint Chiefs of Staff, was informed on Tuesday that Austin had been hospitalized the night before, one U.S. official said.

Austin offered a mea culpa on Saturday, saying in a statement that he "could have done a better job ensuring the public was appropriately informed. I commit to doing better."

"But this is important to say: this was my medical procedure, and I take full responsibility for my decisions about disclosure," he said.

The Pentagon, led by Austin, is currently embroiled in several major international issues including tensions in the Middle East related to the Israel-Hamas war -- which led to the U.S. deploying increased military assets to the region -- and supporting Ukraine as it battles a Russian invasion that began in 2022.