Trump clears South Korean nuclear submarine

U.S. President Donald J. Trump and South Korean President Lee Jae Myung | Photo: The White House

U.S. President Donald Trump announced via social-media that he has authorised South Korea to build a nuclear-powered submarine. “I have given them approval to build a Nuclear Powered Submarine, rather than the old fashioned, and far less nimble, diesel powered submarines that they have now,” he wrote.

The announcement followed a meeting with South Korean President Lee Jae-myung during the APEC summit in Gyeongju. Officials said the submarine is expected to be built at a shipyard in Philadelphia, where South Korean defence firms have invested.

President Lee told Trump: “We don’t mean to build nuclear-armed submarines, but because diesel submarines are less capable of submerged navigation, there are restrictions on tracking North Korean or Chinese submarines.” He added: “So if you allow us to supply fuel… if we build several submarines equipped with conventional weapons… the U.S. military’s burden could be significantly reduced.”

South Korea currently operates a fleet of diesel-electric attack submarines under its KSS-III programme. These boats must surface periodically or use snorkel systems, limiting endurance. Nuclear-powered submarines offer longer submerged endurance, greater speed and operational range—factors cited by Seoul as driving the requirement for escalation.

While the announcement signals preliminary approval, major issues remain unresolved like how the U.S. will transfer nuclear-propulsion technology, arrange enriched-uranium fuel supply, and ensure regulatory coverage under non-proliferation frameworks.

China’s foreign ministry responded by urging both Washington and Seoul to “earnestly fulfil their nuclear non-proliferation obligations and do things to promote regional peace and stability.”