# US-Japan-South Korea trilateral cooperation > Live situation record from CLSTR: https://clstr.news/situations/20260921-us-japan-south-korea-trilateral-cooperation > Updated: 2026-09-22T06:36:14.000Z. Sources: 18. Developments: 3. Foreign ministers from the United States, Japan, and South Korea met in New York during the UN General Assembly to issue a joint statement regarding regional security and economic cooperation. On security matters, the three nations reaffirmed their commitment to the complete denuclearization of North Korea and pledged to disrupt funding for its nuclear and ballistic missile programs, particularly revenue generated through cyber activities. The United States reiterated an “ironclad defense commitment” to Japan and South Korea, including the potential use of its nuclear capabilities to protect its allies. During these discussions, South Korean President Lee Jae-myung advocated for a practical, gradual approach to denuclearization, proposing a process of stopping, reducing, and eventually dismantling activities. Regarding the Indo-Pacific, the ministers reaffirmed the importance of peace and stability in the Taiwan Strait, opposing unilateral attempts to change the status quo. They emphasized adherence to international law, including the United Nations Convention on the Law of the Sea (UNCLOS), to maintain freedom of navigation and overflight. Taiwan’s Ministry of Foreign Affairs expressed gratitude for the statement, noting that stability in the strait is essential for global security and supply chain stability. In a separate interview, Taiwan Vice President Hsiao Bi-khim noted that the relationship between Taiwan and the United States remains solid and addressed challenges regarding cognitive warfare and disinformation. On economic security, the ministers expressed opposition to economic coercion and non-market practices. They established a new trilateral economic security consultation mechanism and pledged cooperation in emerging technologies such as artificial intelligence, semiconductors, and quantum technology. ## Claims - The three nations expressed a firm commitment to the full denuclearization of North Korea. (disputed by 2 sources) - South Korean President Lee Jae-myung proposed a gradual approach to North Korean denuclearization rather than seeking immediate, total disarmament. (disputed) - The US, Japan, and South Korea reaffirmed their commitment to the defense of Japan and South Korea, including the use of US nuclear capabilities. (corroborated by 2 sources) - The trilateral group agreed to cooperate on small modular nuclear reactors for third-country markets. (corroborated by 2 sources) - The ministers emphasized the need to stop funding for North Korea's nuclear and missile programs, including cyber-based funding. (single source) - The ministers called for the peaceful resolution of issues in the Taiwan Strait and opposition to unilateral changes to the status quo. (single source) ## Timeline ### 2026-09-22: US, Japan, and South Korea reaffirm Taiwan Strait stability The US, Japan, and South Korea issued a joint statement reaffirming the importance of peace and stability in the Taiwan Strait and opposing unilateral changes to the status quo. 2 sources. https://clstr.news/cluster/us-japan-and-south-korea-reaffirm-taiwan-strait-stability ### 2026-09-22: US, Japan, and South Korea reaffirm security ties and nuclear deterrence The US, Japan, and South Korea reaffirmed their security alliance, including US nuclear deterrence, while calling for North Korean denuclearization. South Korea's president proposed a gradual disarmament path. 3 sources. https://clstr.news/cluster/us-japan-and-south-korea-pledge-nuclear-backed-defense ### 2026-09-20: US, Japan, and South Korea reaffirm security and economic cooperation US, Japan, and South Korea foreign ministers met in New York to reaffirm North Korean denuclearization goals, strengthen supply chain security, and uphold peace in the Taiwan Strait. 13 sources. https://clstr.news/cluster/south-korea-us-and-japan-to-sign-arctic-cooperation-mou --- Cite as: US-Japan-South Korea trilateral cooperation. CLSTR, https://clstr.news/situations/20260921-us-japan-south-korea-trilateral-cooperation