Recording of US Defence Secretary Lloyd Austin's 911 emergency call released

Officials have released the emergency phone call that led to US Defence Secretary Lloyd Austin being admitted to hospital on New Year's Day.

Mr Austin's delay in telling colleagues and the White House about his cancer and surgery complications has sparked political uproar and investigations.

In the audio, an unidentified caller asked the ambulance not use its lights or sirens and to try be "subtle".

The retired general was released on Monday following two weeks in hospital.

The 70-year-old was admitted to an intensive care unit on 1 January due to complications from "minimally invasive" prostate surgery in December.

The defence secretary is just below the president in the chain of command for the US military.

The heavily redacted four-minute call, released by officials in Virginia on Tuesday after a freedom of information request, shows unidentified callers asking that Mr Austin be transported to Walter Reed National Military Medical Center in Maryland.

"Can the ambulance not show up with lights and sirens? We're trying to remain a little subtle," the caller, whose name was redacted from the audio, told the emergency dispatcher.

Senior defence officials and the White House did not learn that Mr Austin was seriously ill until three days after his re-admission.

That secrecy prompted security and transparency concerns and three investigations have since been launched into the handling of his health crisis. The Pentagon later revealed that Mr Austin had been diagnosed with prostate cancer.

Mr Austin will work remotely from home as he recovers, Pentagon officials say. He is expected to make a full recovery.

Last week, Mr Austin authorised multiple strikes against Yemen-based Houthi militants in the Red Sea from his hospital bed.

On Tuesday, White House Press Secretary Karine Jean-Pierre said the president had spoken to Mr Austin last week over the phone.

"The president is looking forward to the secretary getting back to the Pentagon," Ms Jean-Pierre said. "The secretary was very much engaged and involved in what we're seeing in the Middle East."

While some senior Republicans have urged Mr Biden to dismiss his defence secretary, the president has expressed full confidence in Mr Austin.

But he admitted that the military chief had shown a lapse in judgement by failing to inform the White House that he was in hospital.