U.S. President Joe Biden learned of Defense Secretary Lloyd Austin’s hospitalization last week several days after the fact and received no advance notice from Pentagon officials, people familiar with the matter said.

The Defense Department announced Austin’s hospitalization at Walter Reed Medical Center on Friday, four days after he was admitted on Jan. 1 and without providing specifics on his ailment or the elective treatment he received.

Several U.S. senators privately expressed concern that they weren’t informed sooner. Sen. Tom Cotton, a Republican from Arkansas and U.S. Army veteran, called on Austin to address an earlier news report of the notification gap and said "there must be consequences for this shocking breakdown” if true.