Cambodia Reiterates Firm Position on Colonial‑Era Border, Rejects Changes by Force

PHNOM PENH, June 18, 2026 (KPT) — Cambodia has reaffirmed its firm stance on protecting the international boundary inherited from the colonial era, rejecting any attempt to alter borders through the use of force, government spokesman Pen Bona said Thursday.

“Cambodia maintains a firm position in protecting the Cambodia–Thailand international border as inherited from the Franco‑Siamese Boundary Commission, in accordance with the principles of international law,” Bona told reporters.

He cited the principle of uti possidetis juris — the inviolability of inherited boundaries — and stressed Cambodia’s respect for Franco‑Siamese conventions, treaties, maps and demarcation records, as well as agreements and documents mutually recognised by both countries.

On maritime issues, Bona said Cambodia has invoked compulsory conciliation under the UN Convention on the Law of the Sea to address overlapping claims with Thailand.

“Cambodia does so with strong confidence that this process will demonstrate the true value of international law and peaceful settlement of disputes, while categorically rejecting any alteration of its borders resulting from the use of force,” he added.

The Defence Ministry echoed the position, saying boundary issues must be resolved through formal mechanisms rather than unilateral action. It urged the Cambodia–Thailand Joint Boundary Commission to resume demarcation work promptly to allow displaced residents to return safely.

Cambodia also reaffirmed support for the ASEAN Observer Team, calling for a stronger mandate to ensure full implementation of the ceasefire.