US to Share Nuclear Submarine Technology with South Korea Following Trump-Lee Meeting

Historic Technology Transfer Announced

In a significant development for international defense cooperation, President Donald Trump announced that the United States will share sensitive technology to enable South Korea to construct a nuclear-powered submarine. The announcement was made via social media on Thursday, October 30, 2025, following a bilateral meeting with South Korean President Lee Jae Myung in Gyeongju, South Korea. The leaders convened on the sidelines of the Asia-Pacific Economic Cooperation (APEC) forum.

This decision marks a notable shift in U.S. policy, as the highly classified nuclear submarine technology has historically been closely guarded, with direct transfers previously limited to the United Kingdom in the 1950s.

Strategic Rationale and Economic Commitments

During their meeting, President Lee Jae Myung emphasized South Korea's need for nuclear-powered submarines to modernize the alliance and enhance its capabilities to track submarines from nations like North Korea and China. Lee clarified that South Korea's interest lies in obtaining nuclear fuel for conventionally armed submarines, not nuclear weapons, addressing potential misunderstandings from previous discussions. Diesel-powered submarines, currently in South Korea's fleet, have limited submerged endurance compared to nuclear-powered vessels.

The agreement is also intertwined with substantial economic commitments. South Korea has pledged an investment of $350 billion in the United States, with $150 billion specifically earmarked to bolster U.S. shipbuilding capacity. President Trump indicated that the new South Korean nuclear-powered submarine would be built at the Philadelphia Shipyards, which was acquired last year by South Korea's Hanwha Group. This move is expected to contribute to a resurgence in American shipbuilding.

Geopolitical Implications and Future Outlook

The timing of this announcement comes amidst growing regional security concerns, particularly after North Korea unveiled a nuclear-powered submarine under construction in March. The acquisition of nuclear-powered submarines by South Korea is seen as a measure to fortify U.S. military operations in the Asia-Pacific region and serve as a counterbalance to regional adversaries.

The agreement also included a finalized trade deal between the two nations, which will see tariffs on South Korean goods lowered from 25% to 15%. While the specific dimensions and financial implications of the submarine project remain undefined, and the timeline for construction is unclear, this collaboration underscores a deepening of the U.S.-South Korea alliance in both defense and economic sectors.