US Navy Secretary John Phelan will leave his office.

• US Navy Secretary John Phelan will leave office immediately.
• No explanation was given for the move.
• A number of top US military officials have been dismissed recently.

US Secretary of the Navy John Phelan will leave office “immediately”, the Pentagon announced on Wednesday, without providing an explanation for the sudden exit.

Phelan’s departure follows the removal of top US Army officer General Randy George and two other senior officers earlier this month, at a time when the US is locked in a war with Iran that remains unresolved.

Phelan “is departing the administration, effective immediately”, Pentagon spokesperson Sean Parnell said in a statement on X, adding that he would be replaced in an acting capacity by Undersecretary Hung Cao.

Reuters sources, who spoke on condition of anonymity, said Phelan was dismissed in part because he was moving too slowly to implement reforms to ⁠speed shipbuilding and because he had fallen out with key Pentagon leadership.

One source cited bad relationships with US Secretary of Defence Pete Hegseth, Hegseth’s deputy, Steve Feinberg, as well as the Navy’s No 2 civilian, Cao.

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Since returning to office early last year, US President Donald Trump has overseen a purge of top military personnel, including the chair of the Joint Chiefs of Staff, General Charles “CQ” Brown, whom he fired without explanation in February 2025.

Other senior officers dismissed include the heads of the US Navy and Coast Guard, the general who headed the National Security Agency, the vice chief of staff of the Air Force, a Navy admiral assigned to NATO, and three top military lawyers.

The chief of staff of the Air Force also announced his retirement without explanation just two years into a four-year term, while the head of US Southern Command retired a year into his tenure.

Hegseth has insisted the president is simply choosing the leaders he wants, but Democratic lawmakers have raised concerns about the potential politicisation of the traditionally neutral US military.

In 2025, the Pentagon chief additionally ordered at least a 20% cut in the number of active-duty four-star generals and admirals in the US military, as well as a 10% cut in the overall number of general and flag officers.