Under fire for his secret hospital stay last month, Defense Secretary Lloyd Austin told lawmakers Thursday that the Pentagon has made “institutional changes” after shielding his prostate cancer diagnosis and subsequent hospitalization from Congress and President Biden — but insisted “at no time during my treatment or recovery were there any gaps in authorities.”

“There was never any lapse in authorities or in command and control,” Austin told a House Armed Services Committee hearing. “At all times, either I or the deputy secretary was in the position to conduct the duties of my office.”

“But we did have a breakdown in notifications during my January stay at Walter Reed, that is, sharing my location and why I was there,” he added.

“And back in December, I should have promptly informed the president, my team in Congress and the American people of my cancer diagnosis and subsequent treatment.”

“We did not handle this right,” the 70-year-old Austin added, “and I did not handle it right.”

Both Democrats and Republicans criticized the secretary’s failure to Biden, 81, Austin’s deputy or other senior leaders know about his Jan. 1 hospitalization for complications from prostate cancer surgery.

“It’s totally unacceptable that it took three days to inform the president of the United States that the secretary of defense was in the hospital and not in control of the Pentagon,” said Rep. Mike Rogers (R-Ala.), chairman of the House Armed Services Committee, noting the ongoing wars in Ukraine and the Middle East. 

“The chain of command doesn’t work when the commander in chief doesn’t know who to call,” Rogers added, emphasizing that there needed to be accountability for the lapse in judgment.

“I agree with much of what the chairman said,” added ranking member Adam Smith (D-Wash.), saying “the lack of transparency … should not be repeated.”

But Smith stopped short of saying the concealment of Austin’s health concerns harmed national security.

“We were doing everything that we needed to do to meet the national security needs of this country,” he said. “And if members of this committee incorrectly imply otherwise, they are merely giving aid and comfort to those adversaries that they claim to care about confronting.”

Austin developed complications from a Dec. 22 prostatectomy and was rushed to Walter Reed National Military Medical Center on the evening of New Year’s Day with “severe abdominal, hip and leg pain,” later determined to be from a urinary tract infection.

While incapacitated in the Critical Care Unit the following day, his assistants and assistants to deputy secretary Kathleen Hicks agreed that a “transfer of authorities” was necessary, according to an unclassified summary released Monday by the Pentagon.

Hicks — who did not learn of Austin’s hospitalization until Jan. 4 — was on leave and vacationing in Puerto Rico at the time of the transfer, while the White House and general public only learned of the health scare after the close of business on Friday, Jan. 5.

“You said there was never a break in command and control,” Rep. Elise Stefanik (R-NY) asked Austin, “but yet the president of the United States was not aware that you were outside of the chain of command. So is the president not a part of this command and control?”

“He is clearly at the top of the chain in terms of command and control,” Austin responded, “but what is important is that we provide him with credible options that he can pursue to address any situation and it would’ve happened in this case.”

“Except he was unaware,” Stefanik said, “so what’s important is the president was unaware of this breakdown in command and control and you were not there, in terms of who he would hear from.”

“The president of the United States was not aware that you were not in the chain of command. So God forbid there was a retaliatory strike that would have caused potential delays,” she added.

“Who will be held accountable for this, this embarrassment?” asked Rep. Jim Banks (R-Ind.), pointing out that Austin’s absence of several days proves “either the president is that aloof or you are irrelevant.”

In a news briefing Feb. 1, Austin told reporters the cancer diagnosis “was a gut punch” for him, and “frankly, my first instinct was to keep it private.”

Republicans and at least one Democrat have called on Austin to resign for keeping his chain of command in the dark about his condition.

The internal Pentagon review — conducted by Austin’s subordinates — largely absolved anyone of wrongdoing for the secrecy surrounding his hospitalization, citing “no indication of ill intent or an attempt to obfuscate.” 

Defense Department officials did a classified briefing with senators on Tuesday about Austin’s decision-making process that got mixed reviews.

Senate Armed Services Committee chairman Jack Reed (D-RI) called the review a “starting point” and held the briefing to ensure that communications problems don’t happen again.

Sen. Deb Fischer (R-Neb.) added that the officials had a duty to “consider how to inform Congress about future gaps in command — as required by current law.”

The internal review said procedures must be improved and information shared better when the defense secretary must transfer decision-making authorities to the deputy.

The Defense Department’s inspector general is also conducting a review, which has not yet been completed.

With Post wires