The Acting US Navy Secretary has apologised to the former captain of a coronavirus-stricken aircraft carrier who was removed after he demanded urgent action to halt the spread of the disease on board.

Key points: Captain Brett Crozier was removed over a leaked letter calling for urgent help to stop coronavirus spreading

Captain Brett Crozier was removed over a leaked letter calling for urgent help to stop coronavirus spreading The Navy's top civilian apologises for telling crew their former captain was too "naive" or "stupid"

The Navy's top civilian apologises for telling crew their former captain was too "naive" or "stupid" More than 170 crew on USS Theodore Roosevelt have tested positive to COVID-19

Captain Brett Crozier had called for thousands of sailors to be taken from the USS Theodore Roosevelt and put into isolation, writing that unless the Navy acted immediately it would be failing to properly safeguard "our most trusted asset — our sailors".

The four-page letter described a bleak situation aboard the carrier as more of his crew began falling ill.

After he was removed, videos emerged of the crew applauding Captain Crozier as he left the ship in Guam, and a petition seeking his reinstatement garnered more than 120,000 signatures.

Just days after firing him, he was sharply criticised by the Acting US Navy Secretary, Thomas Modly, in a speech to the crew.

In what was meant to be a private address, he defended his decision to relieve Captain Crozier of his command due to the leaking of the letter pleading for help.

Mr Modly said the letter, and the leak, amounted to a betrayal by the captain, who was responsible one way or another.

He told the crew:

"If he didn't think that information was going to get out into the public in this information age that we live in, then he was A, too naive or too stupid to be a commanding officer of a ship like this. The alternative is that he did it on purpose."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 34 seconds 34 s Sailors gave Captain Brett Crozier a raucous send-off.

Mr Modly, who has faced calls for his own removal, has now issued an apology saying: "I do not think Captain Brett Crozier is naive nor stupid."

The apology, which Mr Modly also extended to the carrier's crew and Captain Crozier's family, was a reversal from a statement the Navy's top civilian issued hours earlier which said: "I stand by every word I said, even, regrettably any profanity that may have been used for emphasis."

Earlier, US President Donald Trump said he might get involved in the deepening crisis in the Navy, saying he may be able to resolve the situation.

"You have two good people and they're arguing ... I'm good at settling these arguments. So I may look into it in great detail, in detail and I'll be able to figure it out very fast," he said.

Captain Crozier should not have sent his letter, but he did not "want to destroy somebody for having a bad day," Mr Trump said.

Sailors have hailed the captain a hero, out to defend his crew at great cost to his career.

More than 170 crew members on the USS Theodore Roosevelt have tested positive to COVID-19.

A sailor on board the ship told the Reuters news agency that Mr Modly's speech only angered the crew.

"Nobody likes what he had to say ... he made everyone more irritated," said the sailor, who spoke on condition of anonymity.

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Captain Crozier's crew members showed their disapproval of Mr Modly's decision by posting videos online last week of their captain's emotional send-off.

About 173 crew members have tested positive for coronavirus so far, possibly including the captain himself.

Mr Modly and the President have both been criticised for the decision to relieve the captain of his command.

Democratic presidential contender Joe Biden said Mr Modly "shot the messenger".

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 20 minutes 20 m The Virus

Reuters/ABC