© Alex Brandon/AP FILE - In this Dec. 3, 2019, file photo, acting Navy Secretary Thomas Modly testifies during a hearing of the Senate Armed Services Committee about about ongoing reports of substandard housing conditions in Washington, on Capitol Hill. Modly says the captain of the COVID-stricken aircraft carrier who was fired last week had betrayed his service and may have been "too naive or too stupid" to be commanding officer of the ship. Officials are confirming that Modly made the comments Sunday, April 5, 2020, to the ship's crew in Guam. (AP Photo/Alex Brandon, File)

Acting Navy Secretary Thomas Modly resigned on Tuesday, a day after leaked audio revealed he called the ousted commander of the USS Theodore Roosevelt "stupid" in an address to the ship's crew, according to a US official and a former senior military official.

The Navy and Department of Defense did not respond to a request for comment. Undersecretary of the Army James McPherson has been tapped to succeed Modly, a US official and a defense official tells CNN. McPherson is a retired rear admiral and was the former judge advocate general of the Navy.

On Monday, Modly told the crew of the Roosevelt that their former commander, Capt. Brett Crozier, was either "too naive or too stupid" to be in command or that he intentionally leaked a memo to the media, in which Crozier warned about coronavirus spreading aboard the aircraft carrier and urged action to save his sailors, according to remarks obtained by CNN.

Late Monday night, Modly apologized in a statement for calling Crozier "stupid" in his earlier remarks.

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"Let me be clear, I do not think Captain Brett Crozier is naive nor stupid. I think, and always believed him to be the opposite," Modly said in his statement. "We pick our carrier commanding officers with great care. Captain Crozier is smart and passionate. I believe, precisely because he is not naive and stupid, that he sent his alarming email with the intention of getting it into the public domain in an effort to draw public attention to the situation on his ship. I apologize for any confusion this choice of words may have caused."

Modly's Monday morning remarks to the crew prompted sailors to yell back in frustration. President Donald Trump said that he might "get involved" in the matter, and Defense Secretary Mark Esper later ordered Modly to apologize, two US officials told CNN.

'A betrayal'

Tuesday's news comes after top members of the House Armed Services Committee began calling for his departure.

Modly relieved Crozier of duty late last week after a memo the captain had written to Navy officials leaked to the press. Crozier wrote of the challenge of trying to contain a coronavirus outbreak aboard the ship and urgently requested that sailors be allowed to quarantine on land.

Modly told the crew that Crozier had to go, citing loss of confidence and a failure to adhere to the chain of command. It was a "betrayal of trust, with me, with his chain of command," he said in remarks that were piped over the vessel's public address system.

Modly also suggested Crozier leaked the memo on purpose or was "too naive or too stupid" to be in command if he didn't think that sending it to over 20 people would not result in it getting out to the public.

"If he didn't think, in my opinion, that this information wasn't going to get out to the public, in this day and information age that we live in, then he was either a) too naïve or too stupid to be a commanding officer of a ship like this," Modly said. "The alternative is that he did this on purpose."

At least 230 sailors aboard the Roosevelt had tested positive for coronavirus as of Tuesday morning, an increase of 57 cases since the day before, a US Navy official told CNN.

Officials at the Pentagon are split about whether Crozier should have been relieved, but most feel the situation was badly handled and is now causing additional problems at an already difficult time.

At a Monday briefing, Trump was asked about Modly's comments.

"I haven't heard it exactly, I heard they heard," Trump said, referring to the crew of the USS Theodore Roosevelt. "I heard they had a statement that was made, if that were the statement, it's a strong statement."

"The letters shouldn't have been sent, and certainly they shouldn't have been leaked," Trump said of Crozier's memo. "I've heard very good things about the gentlemen. Both gentlemen, by the way, I will say this, about both gentlemen. And I may look into it from the standpoint of something should be resolved because I'm hearing good things about both people."

Trump added that he "may just get involved."

Shortly afterward, Modly moved into damage control mode, but his apology still insinuated that Crozier had deliberately leaked the memo himself.

"I believe, precisely because he is not naive and stupid, that he sent his alarming email with the intention of getting it into the public domain in an effort to draw public attention to the situation on his ship. I apologize for any confusion this choice of words may have caused," he said.

Modly also apologized directly to Crozier for "any pain my remarks may have caused."

"(Crozier and his family), and the entire Navy, have my full commitment that I will continue to help get the TR back to full health and back to sea where we can move forward beyond this unfortunate situation," he said.

This breaking story has been updated to reflect Undersecretary of the Army James McPherson has been named as Modly's successor after he resigned.