The move follows a Thai government decision last month to unilaterally terminate a 2001 agreement with Cambodia that provided a framework for negotiations over the disputed area in the Gulf of Thailand, where the two countries’ maritime claims overlap.

“We have taken this step to protect Cambodia’s sovereignty and maritime rights in accordance with international law,” Cambodian Prime Minister Hun Manet said.

Thailand’s cancellation was part of a campaign pledge by Thai Prime Minister Anutin Charnvirakul, who won re-election in February on a wave of nationalistic sentiment, after two rounds of deadly military clashes between the countries last year along their disputed border.

Under the UN Convention on the Law of the Sea, or UNCLOS, a compulsory conciliation process allows a panel of independent experts to examine a dispute and make recommendations, although its findings are not legally binding on either party.