By Phil Stewart and Idrees Ali

WASHINGTON (Reuters) -Republican lawmakers slammed U.S. Defense Secretary Lloyd Austin at a hearing on Thursday for failing to disclose his prostrate cancer surgery and subsequent hospitalization to President Joe Biden and even his deputy at the Pentagon.

Austin, with support from Democrats on the House of Representatives Armed Services committee, sought to dispel accusations that his absence jeopardized national security or demonstrated any lack of influence he might have in Biden's Democratic administration.

But Republicans questioned how Biden could go for days without knowing Austin was hospitalized.

"I find it very concerning that the secretary could be hospitalized for three days without anyone else in the administration even noticing," said Representative Mike Rogers, the committee's chairman.

"That suggests Secretary Austin's advice is not sought or heeded in the White House, even while military operations were ongoing in the Middle East."

Instead of disclosing his health situation, Austin opted to keep secret his initial prostate cancer surgery in December as well as a subsequent January hospitalization for post-surgical complications that landed him in the intensive care unit.

Austin has apologized for the way he handled the matter, including to Biden himself, but his appearance before the committee was the first time lawmakers could directly question him.

The hearing was one of the most contentious and personal that Austin, a retired four-star general, has faced in his career.

Representative Jim Banks, a Republican, called the secret hospitalization an embarrassment, and chided him for holding no one accountable. He pointed to Chinese and Russian accounts that portrayed chaos and mismanagement at the Pentagon.

"What you've done has embarrassed us," Banks said.

The Pentagon released the results from an internal 30-day review on Monday that effectively absolved itself of any wrongdoing. It concluded that "nothing examined during this review demonstrated any indication of ill intent or an attempt to obfuscate."

The failure to hold anyone accountable infuriated several lawmakers. Rogers criticized the report for failing to provide real answers for who knew what, when and who failed to perform their basic duties.

"We were led to believe your 30-day internal review would shed light on the matter," Rogers said.

  "But it includes no explanation of why the president and his staff were left in the dark. It makes no recommendations to improve communication with the White House. And, unsurprisingly, it holds no one accountable."

At a rare press briefing earlier in February, Austin, who is intensely private, took responsibility for failing to tell Biden and senior staff about his prostate cancer diagnosis ahead of time, adding that the health scare was a "gut punch" that had shaken him.

Soon after the secret hospitalizations were revealed, both Republican and Democratic lawmakers criticized Austin for failing to disclose the cancer diagnosis and subsequent hospitalizations. Some prominent Republicans, including former President Donald Trump, called for Austin to be removed from his post.

"Are you surprised the president didn't call for your resignation? I'm surprised," Banks said.

Austin responded: "The president has expressed full faith and confidence in me."

(Reporting by Phil Stewart and Idrees Ali; Editing by Alistair Bell and Jonathan Oatis)