It took the Pentagon three and a half days to inform the White House that Defense Secretary Lloyd J. Austin III had been hospitalized on New Year’s Day following complications from an elective procedure, two U.S. officials said Saturday.
The extraordinary breach of protocol — Mr. Austin is in charge of the country’s 1.4 million active-duty military at a time when the wars in Gaza and Ukraine have dominated the American national security landscape — has baffled officials across the government, including at the Pentagon.
Senior defense officials say Mr. Austin did not inform them until Thursday that he had been admitted to the intensive care unit at Walter Reed National Military Medical Center in Bethesda, Md. The Pentagon then informed the White House.
The Pentagon’s belated notification, first reported by Politico, confounded White House officials, one Biden administration official said. A spokeswoman for the National Security Council declined to comment on Saturday.
On Saturday night, Mr. Austin issued a mea culpa.
“I recognize I could have done a better job ensuring the public was appropriately informed,” he said in a statement. “I commit to doing better.”
Mr. Austin added, “This was my medical procedure, and I take full responsibility for my decision about disclosure.”
President Biden and Mr. Austin spoke by telephone Saturday night, a U.S. official said, adding that the president was glad to hear that Mr. Austin is recovering. Another official said that the president has full confidence in his defense secretary. The officials spoke on condition of anonymity because of the sensitive situation.
It was late Friday evening when Mr. Austin’s spokesman, Maj. Gen. Patrick S. Ryder, put out a statement to the news media that the secretary had been hospitalized. General Ryder said patient privacy prevented him from elaborating about Mr. Austin’s medical issue.
In the Friday statement, he said the defense secretary, who is 70, was “recovering well and is expecting to resume his full duties today.”
Mr. Austin was still in the hospital on Saturday, a defense official said.
Pentagon officials had to call Deputy Defense Secretary Kathleen Hicks while she was on vacation in Puerto Rico to handle affairs while Mr. Austin was hospitalized, a Defense Department official said on Saturday, confirming a report by NBC News. The department said on Friday that Ms. Hicks had assumed Mr. Austin’s duties temporarily. The secretary has delegated authority to her in the past, when he has been on vacation and off the grid.
But just Thursday, while Mr. Austin was out of action, the United States launched a retaliatory strike in Baghdad that killed a militia leader who Pentagon officials said was responsible for recent attacks on American troops in the region.
A Biden administration official said that the head of U.S. Central Command, Gen. Michael E. Kurilla, already had authorization for the strike.
Senator Tom Cotton, Republican of Arkansas and a member of the Armed Services Committee, demanded on Saturday that Mr. Austin explain why he had not immediately informed the White House that he had been hospitalized and was unable to perform his duties.
“The secretary of defense is the key link in the chain of command between the president and the uniformed military, including the nuclear chain of command, when the weightiest of decisions must be made in minutes,” Mr. Cotton said in a statement. “If this report is true, there must be consequences for this shocking breakdown.”
Criticism was growing in other quarters as well.
“The public has a right to know when U.S. cabinet members are hospitalized, under anesthesia or when duties are delegated as the result of any medical procedure,” the Pentagon Press Association said in a statement Friday night. “As the nation’s top defense leader, Secretary Austin has no claim to privacy in this situation.”
Mr. Austin is notoriously private and has kept a low profile during his time as defense secretary. It has been more than a year since he appeared at the lectern in the Pentagon briefing room to address members of the news media, and he has been known to sometimes avoid reporters who travel with him overseas.
On those trips, he prefers to dine alone in his hotel room when he does not have an engagement with a foreign counterpart.
In his statement Saturday, Mr. Austin said, “I am very glad to be on the mend and look forward to returning to the Pentagon soon.”
Zolan Kanno-Youngs contributed reporting.