The US defense secretary, Lloyd Austin, was released from hospital on Monday, two weeks after he was admitted for complications following prostate cancer surgery, apparently leaving the White House unaware of his absence for three days, Report informs via The Guardian.

In a statement, the Pentagon said the most senior US military official will work remotely “for a period of time” before returning to the office and has “full access” to secure communications capabilities.

“Secretary Austin’s prostate cancer was treated early and effectively, and his prognosis is excellent,” Austin’s doctors at Walter Reed national military medical center said in a statement.

Austin said in a statement that he was “grateful for the excellent care I received” and that “as I continue to recuperate and perform my duties from home, I’m eager to fully recover and return as quickly as possible to the Pentagon.”

Austin underwent a prostate procedure in December and was again hospitalized on January 1 for complications. But the Pentagon did not release any notification about his absence until January 5. It later came out that Austin had not notified Congress or the White House about his diagnosis or treatments.

That prompted a political backlash, including an investigation by the defense department inspector general. The Pentagon later said the general’s chief of staff was sick with the flu at the time.

The National Security Council spokesperson John Kirby said Austin’s participation in national security affairs “was no different than it would be on any other given day, except that he was briefing the president on options and engaged in the discussions from the hospital”.

But the appearance that the links in a crucial chain of command during a moment of rising global tensions and US military action against Iran-backed militias in Iraq, Syria and Yemen caused significant concern about communications within the administration.

On his 12th day in hospital, last Thursday, Austin reportedly orchestrated and then watched in real time as US retaliatory strikes against Houthi militias was launched.

That came as the Senate armed services committee chair, Jack Reed, a Democrat, and his counterpart, the Republican senator Roger Wicker, sent a letter to Austin asking for an accounting of his absences from defense department headquarters.

“We are concerned that critical notification procedures were not followed while you were receiving medical care the past several weeks,” they wrote, adding that their committee “has serious questions about this incident, and members need a full accounting to ensure it never happens again”.

A day later, on Friday, Joe Biden was asked if the delay in notification of Austin’s absence was a lapse of judgement. “Yes”, the US president said.