Seoul says nuclear submarine possible within 15 years

SEOUL

Protesters shout slogans, demanding the U.S. not help South Korea acquire nuclear-powered submarines, while gathering near the Defense Ministry in Seoul, South Korea, Tuesday, Nov. 4, 2025. (AP Photo/Lee Jin-man)

South Korea expects to launch its first nuclear-powered submarine by the late 2030s, a senior Defense Ministry official told ministers Tuesday, days after Washington had approved Seoul's plans.

U.S. President Donald Trump last week said he had given ally Seoul a green light, after South Korea had announced that the two countries reached a broad deal covering investment and shipbuilding.

Trump, who was in South Korea for a regional summit, said on Truth Social that Seoul would manufacture its nuclear-powered submarine in "the Philadelphia Shipyards, right here in the good ol' U.S.A."

U.S. nuclear submarine technology is considered among the most sensitive and tightly guarded military secrets.

Unlike diesel-powered submarines which must surface regularly to recharge their batteries, nuclear-powered ones can remain submerged for far longer periods of time.

Seoul has not commented on Trump's remarks suggesting the submarine would be built on US soil.

Senior Defense Ministry official Won Chong-dae, however, said Tuesday that it was "feasible to construct a nuclear-powered submarine with our own technology."

"If we secure the submarine fuel through consultations with the United States and enter the construction phase in the late 2020s, we expect to launch the lead vessel by the mid to late 2030s," Won told a cabinet meeting.

"South Korea already possesses world-class design and construction capabilities for conventional submarines," he said.