South Korea and the United States held inaugural talks this week to discuss nuclear cooperation under a joint fact sheet on security agreed by US President Donald Trump and South Korean leader Lee Jae Myung last year, Seoul said on Wednesday.

The talks, held on Tuesday and Wednesday, were due to cover Seoul’s push for expanded uranium enrichment and spent-fuel reprocessing rights to support its plan to build nuclear-powered submarines, South Korea’s Foreign Ministry said previously.

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South Korea’s delegation was led by First Vice Foreign Minister Park Yoon-joo, while the US side was headed by Allison Hooker, the State Department’s under secretary for political affairs, the ministry said.

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The meeting agenda included both “the issue of expanding enrichment and reprocessing rights” and “the issue of nuclear-powered submarines,” ministry spokesperson Park Il told a briefing on Tuesday.

Park said discussions on enrichment and reprocessing were tied to revising the existing nuclear agreement and were “purely for civilian and commercial purposes.”

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By contrast, nuclear-powered submarines would require a separate track since they involve military use of nuclear material, he said. “Because nuclear-powered submarines are related to the military use of nuclear energy, a separate agreement will be needed under US energy law,” Park said.

The two countries agreed to work toward producing substantive results as soon as possible, establish a framework to review progress during the year, and accelerate future consultations, the ministry said on Wednesday.

The US-South Korea joint fact sheet issued in November said Washington supported a process that could lead to South Korea’s civil uranium enrichment and spent-fuel reprocessing for peaceful uses. It also said the US had approved South Korea building nuclear-powered attack submarines and would work with Seoul on requirements, including fuel sourcing.

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South Korea aims to launch its first nuclear-powered submarine by the mid-2030s, using low-enriched uranium fuel and building the vessel domestically, Defence Minister Ahn Gyu-back said last month.

Under the current nuclear agreement between the countries, South Korea is not allowed to reprocess spent nuclear fuel, or to enrich uranium for military purposes, even though it possesses nuclear reactors to generate power.