Technology
Donald Trump Makes Nuclear Submarine Deal with South Korea
The United States will share nuclear-powered submarine technology with South Korea, President Donald Trump said Thursday, marking a potentially historic expansion of military cooperation between the two allies. Trump announced the move on social media following his meeting Wednesday with South Korean President Lee Jae Myung in Seoul.
Lee told reporters that the discussion focused on modernizing the U.S.-South Korea alliance and ensuring a fairer defense burden. He said the agreement centered on access to nuclear fuel technology for submarines, not nuclear weapons. Equipping South Korea with nuclear-powered submarines, Lee said, would strengthen regional security and enhance cooperation with U.S. naval operations in the Pacific.
Why It Matters
The sharing of nuclear submarine technology represents a major policy shift for Washington, which has long guarded such information as among its most classified military secrets. Even under the AUKUS agreement with Britain and Australia, the United States did not directly transfer nuclear submarine know-how to its partners.
President Donald Trump shakes hands with South Korean President Lee Jae Myung as he receives a gift of a gold crown and an award of the Grand Order of Mugunghwa, not seen, during a high honor ceremony at the Gyeongju National Museum in Gyeongju, South Korea, Wednesday, Oct. 29, 2025. (AP Photo/Mark Schiefelbein)
U.S. defense officials have previously cautioned that any transfer of nuclear propulsion technology would require significant safeguards and congressional review.
What To Know
Trump said in a separate post that the submarine would be built at the Philly Shipyard, which South Korea’s Hanwha Group purchased last year. The size and cost of the project were not immediately clear, though South Korea has already pledged $150 billion to boost U.S. shipbuilding capacity as part of broader defense industry investment talks.
The submarine announcement was part of South Korea’s announced $350 billion investment in the American economy following a day of negotiations and formal ceremonies. The events included Lee presenting President Trump with a gold medal and crown, gestures of goodwill as the two leaders worked to secure financial commitments during the final stop of Trump’s trip to Asia.
South Korean Trade Minister Kim Yong-beom said Wednesday that the United States and South Korea agreed to maintain reciprocal tariffs at 15%, the same rate applied since August. The two nations also decided to extend that rate to automobiles and auto parts — South Korea’s top exports to the U.S. — which had previously faced a 25% tariff, disadvantaging automakers such as Hyundai and Kia against Japanese and European rivals.
Trump’s announcements with South Korea comes ahead of his planned meeting with Chinese President Xi Jinping and follows North Korea’s recent unveiling of a nuclear-powered submarine under construction. Pyongyang’s continued weapons development — including cruise missile tests reported Wednesday — has raised new security concerns in the region.
Pentagon officials did not immediately respond to Associated Press requests for comment on Trump’s statement or confirm any formal agreement.
What People Are Saying
Trump said on Truth Social, “South Korea has agreed to pay the USA 350 Billion Dollars for a lowering of the Tariff’s charged against them by the United States. Additionally, they have agreed to buy our Oil and Gas in vast quantities, and investments into our Country by wealthy South Korean Companies and Businessmen will exceed 600 Billion Dollars. Our Military Alliance is stronger than ever before and, based on that, 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. A great trip, with a great President of South Korea!”
Trump said in a separate post, “South Korea will be building its Nuclear Powered Submarine in the Philadelphia Shipyards, right here in the good ol’ U.S.A. Shipbuilding in our Country will soon be making a BIG COMEBACK. Stay tuned!!! President DJT”
What Happens Next
The move underscores Trump’s broader effort to realign alliances and counter growing Chinese and North Korean influence in the Indo-Pacific, while deepening South Korea’s role as a key defense and industrial partner.
This is a breaking news article. Updates to follow.
Updates: 10/29/25, 7:32 p.m. ET: This article was updated with new information and remarks.
The United States will share nuclear-powered submarine technology with South Korea, President Donald Trump said Thursday, marking a potentially historic expansion of military cooperation between the two allies. Trump announced the move on social media following his meeting Wednesday with South Korean President Lee Jae Myung in Seoul.
Lee told reporters that the discussion focused on modernizing the U.S.-South Korea alliance and ensuring a fairer defense burden. He said the agreement centered on access to nuclear fuel technology for submarines, not nuclear weapons. Equipping South Korea with nuclear-powered submarines, Lee said, would strengthen regional security and enhance cooperation with U.S. naval operations in the Pacific.
Why It Matters
The sharing of nuclear submarine technology represents a major policy shift for Washington, which has long guarded such information as among its most classified military secrets. Even under the AUKUS agreement with Britain and Australia, the United States did not directly transfer nuclear submarine know-how to its partners.
President Donald Trump shakes hands with South Korean President Lee Jae Myung as he receives a gift of a gold crown and an award of the Grand Order of Mugunghwa, not seen, during a high honor ceremony at the Gyeongju National Museum in Gyeongju, South Korea, Wednesday, Oct. 29, 2025. (AP Photo/Mark Schiefelbein)
U.S. defense officials have previously cautioned that any transfer of nuclear propulsion technology would require significant safeguards and congressional review.
What To Know
Trump said in a separate post that the submarine would be built at the Philly Shipyard, which South Korea’s Hanwha Group purchased last year. The size and cost of the project were not immediately clear, though South Korea has already pledged $150 billion to boost U.S. shipbuilding capacity as part of broader defense industry investment talks.
The submarine announcement was part of South Korea’s announced $350 billion investment in the American economy following a day of negotiations and formal ceremonies. The events included Lee presenting President Trump with a gold medal and crown, gestures of goodwill as the two leaders worked to secure financial commitments during the final stop of Trump’s trip to Asia.
South Korean Trade Minister Kim Yong-beom said Wednesday that the United States and South Korea agreed to maintain reciprocal tariffs at 15%, the same rate applied since August. The two nations also decided to extend that rate to automobiles and auto parts — South Korea’s top exports to the U.S. — which had previously faced a 25% tariff, disadvantaging automakers such as Hyundai and Kia against Japanese and European rivals.
Trump’s announcements with South Korea comes ahead of his planned meeting with Chinese President Xi Jinping and follows North Korea’s recent unveiling of a nuclear-powered submarine under construction. Pyongyang’s continued weapons development — including cruise missile tests reported Wednesday — has raised new security concerns in the region.
Pentagon officials did not immediately respond to Associated Press requests for comment on Trump’s statement or confirm any formal agreement.
What People Are Saying
Trump said on Truth Social, “South Korea has agreed to pay the USA 350 Billion Dollars for a lowering of the Tariff’s charged against them by the United States. Additionally, they have agreed to buy our Oil and Gas in vast quantities, and investments into our Country by wealthy South Korean Companies and Businessmen will exceed 600 Billion Dollars. Our Military Alliance is stronger than ever before and, based on that, 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. A great trip, with a great President of South Korea!”
Trump said in a separate post, “South Korea will be building its Nuclear Powered Submarine in the Philadelphia Shipyards, right here in the good ol’ U.S.A. Shipbuilding in our Country will soon be making a BIG COMEBACK. Stay tuned!!! President DJT”
What Happens Next
The move underscores Trump’s broader effort to realign alliances and counter growing Chinese and North Korean influence in the Indo-Pacific, while deepening South Korea’s role as a key defense and industrial partner.
This is a breaking news article. Updates to follow.
Updates: 10/29/25, 7:32 p.m. ET: This article was updated with new information and remarks.
