The United States has formally approved South Korea’s plan to build nuclear-powered submarines, announcing that the two allies will cooperate on shipbuilding, fuel, and higher levels of nuclear technology. The move comes as part of a sweeping trade and security agreement finalized in November 2025.
Under the deal, South Korea will invest heavily in U.S. shipbuilding, with roughly US$150 billion committed, and it will work with American counterparts to develop at least four conventionally armed, nuclear-powered submarines by the mid-2030s.
Crucially, Washington has agreed to help Seoul secure the fuel needed to run these submarines, something that has long been a sticking point in previous talks. The agreement also includes support for expanding South Korea’s authority to enrich uranium and reprocess spent nuclear fuel, both sensitive technologies typically restricted under older bilateral nuclear energy pacts.
Both countries have committed to working through a “shipbuilding working group” tasked with building out design, supply chains, and industrial capacity. The agreement folds in strong economic incentives: in return for U.S. support on the submarine program, America will lower its trade tariffs on South Korean cars to 15%.
For South Korea, having nuclear-powered submarines would be a major strategic upgrade. Diesel-powered subs must surface regularly, making them more vulnerable. Nuclear-powered subs, by contrast, can stay submerged for much longer, boosting Seoul’s ability to track adversarial submarines, particularly those deployed by North Korea and China.
From a geopolitical angle, the decision signals a deepening of the U.S.-ROK alliance. Analysts say it’s a significant step in reshaping South Korea’s defense posture and industrial base, turning its shipyards and nuclear infrastructure into major players in advanced naval technology.
However, there are also diplomatic and non-proliferation challenges. China has expressed concern, warning that such a partnership crosses into highly sensitive security territory. And while Trump’s messaging was strong, agreeing to share this type of technology has traditionally been avoided by Washington, particularly when it comes to propulsion and enrichment capabilities.
As both countries work out technical details, where to build the vessels, how to secure fuel and reactor components, how they manage these challenges will shape not just naval power but strategic balance in East Asia for decades.
More Read
Kenya uncovers US$18,000 scheme that has lured 200 citizens into fighting for Russia
