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

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 U.S. 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.