Cambodia to pursue compulsory conciliation under UNCLOS if Thailand revokes MoU

National
04 May, 2026Raksmey Hong

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Foreign ministry secretary of state Kung Phoak Cambodia has expressed Cambodia’s ‘deep disappointment’ over Bangkok’s planned unilateral withdrawal from a 2001 maritime MoU. AKP
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Cambodia has announced its intention to pursue a compulsory conciliation mechanism under the UN Convention on the Law of the Sea (UNCLOS), should Thailand proceed with plans to revoke the 2001 Memorandum of Understanding, a senior foreign affairs official has said, signalling a shift from bilateral negotiations to international legal channels.

In a special interview broadcast on state-run Television of Cambodia (TVK) on May 3, secretary of state at the Ministry of Foreign Affairs and International Cooperation Kung Phoak expressed “deep disappointment” over reports that Bangkok is preparing to unilaterally terminate the 2001 Memorandum of Understanding (MOU 2001).

He explained that the framework has underpinned maritime negotiations between the two countries for more than two decades.

“We are very disappointed that the Thai side is considering unilaterally withdrawing from the MOU 2001,” he said, describing the agreement as “the only bilateral framework that both parties have relied upon for more than two decades” to manage overlapping claims in the Gulf of Thailand.

Signed in Phnom Penh in June 2001, the MOU was designed to address competing maritime claims through a “package deal” approach — combining boundary delimitation with joint development of offshore oil and gas resources — without prejudicing either side’s sovereignty.

Phoak warned that a unilateral withdrawal would effectively dismantle a long-standing mechanism rooted in “cooperation and mutual goodwill”, raising uncertainty over how future disputes would be managed.

“If the Thai side unilaterally withdraws from this memorandum, Cambodia would be left with no choice but to rely upon international law,” he said, pointing specifically to UNCLOS and its compulsory conciliation mechanism for dispute resolution.

“This reflects our sincere hope that both countries can reach a fair, just and lasting solution in line with international law,” he added, stressing Cambodia’s commitment to peaceful settlement.

Thailand seeks ‘reset’ after stalled progress

Thai senior officials have framed the potential withdrawal as a necessary step to revive long-stalled negotiations.

According to Thai media reports, foreign minister Sihasak Phuangketkeow is expected to submit a proposal to the Cabinet on May 5 to terminate the MOU and shift future talks towards UNCLOS-based negotiations.

The move is intended to unlock what the Thais described as a “prolonged impasse” after more than 20 years of limited progress, while laying the groundwork for renewed cooperation, particularly in the energy sector.

Thai government spokesperson Rachada Dhnadirek has noted that only five formal rounds of negotiations have taken place since the agreement was signed, with no concrete outcomes.

Prime Minister Anutin Charnvirakul has also reportedly backed the move, citing the lack of tangible results under the current framework.

Legal shift gains momentum

The Cambodia National Assembly approved accession on January 16, with the convention entering into force for Cambodia on March 8, making the Kingdom the 172nd State Party.

Minister of Information Neth Pheaktra has described UNCLOS as a “comprehensive legal basis” for managing maritime affairs, often referred to as the “constitution of the ocean”.

“UNCLOS is the primary international legal instrument that sets out in detail and comprehensively the rules of the law of the sea,” he said in a recent statement, adding that ratification would bring “significant benefits to the Kingdom of Cambodia as a maritime nation”.

Analysts say the convergence of Thailand’s proposed shift and Cambodia’s recent accession signals a broader transition from bilateral diplomacy to a rules-based international framework.

Former diplomat Pou Sothirak noted that the 2001 agreement was forged during a period of strong political goodwill, allowing both sides to pursue joint development without settling sovereignty disputes.

“At that time, there was mutual understanding and political will to solve overlapping claims through joint development,” he said. “We agreed not to prejudice sovereignty and to share benefits.”

However, he acknowledged that the mechanism has remained largely inactive.

Equal footing under international law

Legal experts argue that UNCLOS places both countries on equal footing, while providing clearer protections against unilateral actions in disputed waters.

“What Cambodia has in UNCLOS is not a bilateral agreement — it is a maritime constitution adopted by the international community,” Sothirak said. “Anything that Thailand has as a right under UNCLOS, Cambodia has the same right.”

He added that the convention offers legal recourse if disputes escalate.

“If Thailand were to act unilaterally in an overlapping area, Cambodia can object and bring a legal complaint,” he said. “UNCLOS contains provisions that prevent such unilateral decisions.”

Researcher Dany Channraksmeychhoukroth noted that the convention establishes a comprehensive framework governing maritime zones, including territorial seas, exclusive economic zones and continental shelves, while also providing structured mechanisms for dispute resolution.

“UNCLOS ensures that disputes can be resolved based on law rather than power,” she said.

Strategic implications

With a coastline of around 400 kilometres, Cambodia’s maritime claims carry significant economic and environmental stakes, including fisheries and potential offshore oil and gas reserves.

Analysts say the shift towards UNCLOS could strengthen Cambodia’s ability to defend its rights on the international stage, particularly as bilateral arrangements face growing uncertainty.

Sothirak likened the convention to an “insurance policy” for the Kingdom’s maritime interests.

“The law will judge based on evidence and proof,” he said. “This ensures that Cambodia’s resources and rights remain protected under international standards.”

As Thailand moves closer to a decision, the future of the MOU 2001 appears increasingly uncertain — and with it, a turning point in how the two neighbours manage one of their most sensitive and long-running disputes.