South Korean President Lee Jae Myung and Mexican President Claudia Sheinbaum signed the Korea-Mexico Joint Action Plan 2026–2030 in Mexico City on Thursday, committing both nations to deeper collaboration across defence, artificial intelligence, crude oil supply chains, and critical natural resources. The two leaders also concluded negotiations on a revised Bilateral Investment Treaty and signed 17 memorandums of understanding spanning aerospace, defence technology, and economic cooperation, with Seoul pledging to help modernise Mexico's military and explore joint entry into third-country arms markets. The summit — Lee's first state visit to Mexico and the first by a South Korean president in 16 years — signals a significant broadening of ties between two major middle powers that also expressed shared support for multilateralism and peaceful resolution of conflicts.