Cambodia launches a compulsory conciliation mechanism under the UN Convention on the Law of the Sea (UNCLOS) to resolve an overlapping maritime boundary dispute with Thailand in the Gulf of Thailand. Cambodia says it has informed the United Nations and Thailand and has sent an official letter to the Thai side. The move follows Thailand’s decision in May to unilaterally end a 2001 bilateral framework agreement governing talks over the contested maritime area and related energy exploration.

Thailand signals it will participate in the UNCLOS process chosen by Cambodia. Thai Foreign Minister Sihasak Phuangketkeow says Bangkok will cease other bilateral talks while the conciliation is under way, according to reporting. At the same time, Thailand expresses concern that the dispute process could affect bilateral efforts to rebuild trust and improve relations.

The dispute has been ongoing for more than 25 years, with both countries claiming a sizable area of overlapping waters. Multiple outlets describe Cambodia’s action as an “internationalization” of the dispute after the breakdown of the 2001 talks framework, and frame Thailand’s participation as conditional on proceeding through the UN-backed mechanism.