PHNOM PENH, Cambodia (AP) - Cambodia's government has submitted formal notice under a U.N. maritime treaty calling for compulsory conciliation to settle a sea boundary disagreement with Thailand, Prime Minister Hun Manet announced on Tuesday.

The contested area is believed to hold substantial reserves of natural gas and other energy resources that both nations seek to develop.

The move to invoke the U.N. Convention on the Law of the Sea follows Thailand's decision last month to cancel a 25-year-old memorandum of understanding that had aimed to manage the overlapping claims.

Thailand ended the pact unilaterally in May after relations soured due to armed clashes along the land border the previous year.

Those clashes fueled nationalist sentiment in Thailand and increased pressure on Prime Minister Anutin Charnvirakul to withdraw from the agreement.

Speaking during a live television address, Hun Manet confirmed that official notification had been sent to both Thailand and the U.N. secretary-general to launch the conciliation process under the treaty.

"Cambodia has never violated the sovereignty of other states," he said.

"At the same time, we remain firmly committed to protecting Cambodia's sovereignty. We fulfill this duty today not by force but through international law, and not by acting alone but by engaging peacefully."

The timing for any proceedings under the process remains uncertain at this stage.

Anutin told reporters that Cambodia's filing posed no immediate difficulty, though he noted Thailand prefers bilateral discussions and had already signaled its intent to follow UNCLOS procedures without compulsory steps.

Any outcome from the conciliation would not carry binding force on either party despite both countries having joined the treaty.

Thailand generally prefers direct negotiations over third-party rulings on territorial matters, partly due to lingering dissatisfaction with a 1962 International Court of Justice decision that awarded Cambodia the Preah Vihear temple site.