WASHINGTON — Secretary of the Navy John Phelan is exiting his post overseeing the service, according to the Pentagon.
“Secretary of the Navy John C. Phelan is departing the administration, effective immediately,” Pentagon spokesperson Sean Parnell said in a social media post today. “On behalf of the Secretary of War and Deputy Secretary of War, we are grateful to Secretary Phelan for his service to the Department and the United States Navy. We wish him well in his future endeavors. Undersecretary Hung Cao will become Acting Secretary of the Navy.”
No additional details were immediately provided about the first departure for a high-ranking political appointee at the Pentagon under the second Trump administration. The Navy referred Breaking Defense’s questions to the Office of the Secretary of Defense, which declined to comment beyond Parnell’s post.
The surprise announcement comes on the heels of Phelan’s high-profile appearance at the Sea-Air-Space Exposition in National Harbor, Md., this week, where he touted the Trump-class battleship and labeled it a necessary for President Donald Trump’s Golden Fleet initiative.
“I’ve heard the critiques: too vulnerable, too expensive, too big,” Phelan said during his keynote address on Tuesday. “We’ve heard that before about carriers and about submarines. And yet, when it matters most, those are the platforms combatant commanders call for first.”
The Navy secretary offered no hint publicly that his time at the helm was running short.
Phelan, who the Senate confirmed as secretary of the Navy in March 2025, has a background in business and previously co-founded and co-managed Partner of MSD Capital, LP, a private investment firm representing the founder and CEO of Dell Technologies, Michael Dell.
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Cao, who first joined the Navy as a seaman recruit in 1989 and subsequently graduated from the US Naval Academy in 1996, spent more than 20 years as a naval officer and completed deployments to Iraq, Afghanistan, and Somalia. After retiring from the service as a captain, he became a vice president and client executive at CACI International. The Senate confirmed him to his post as Under Secretary of the Navy in October 2025.
This is a breaking news story and will be updated.