Amid tensions in the Middle East, US Secretary of Defense Lloyd Austin was hospitalized, including spending four days in the intensive care unit, according to two senior administration officials, Report informs via NBC News.

The Pentagon did not inform senior officials in the White House’s National Security Council of Austin’s hospitalization until Thursday — three days after he arrived at Walter Reed Medical Center, a US official confirms. Politico first reported the delay.

Austin was admitted to the hospital Monday night for “complications following a recent elective medical procedure,” Pentagon press secretary Maj. Gen. Pat Ryder said in a statement Friday evening.

Austin released a statement Saturday taking responsibility for not disclosing his condition sooner.

"I am very glad to be on the mend and look forward to returning to the Pentagon soon. I also understand the media concerns about transparency and I recognize I could have done a better job ensuring the public was appropriately informed. I commit to doing better," Austin said. "But this is important to say: this was my medical procedure, and I take full responsibility for my decisions about disclosure.”

President Joe Biden spoke with Austin on Saturday evening, according to a senior administration official, who indicated it was the first phone call between the president and Austin since his hospitalization.

“It was a warm conversation,” the senior administration official said. “The President wished him the best in his recovery and said he looks forward to seeing the Secretary back at the Pentagon soon.”

Austin was not able to perform his duties since New Year’s Day, a senior defense official said Friday. It was unclear when he would be released, the source said. Details about what ailed him were unavailable.

Ryder told NBC News that Austin “resumed his full duties” on Friday evening. He remained hospitalized Saturday.

Deputy Secretary of Defense Kathleen Hicks, who was on leave, has picked up his duties, the senior defense official said.