Background
The Cambodia–Thailand Joint Boundary Commission (JBC) is the bilateral mechanism responsible for conducting land demarcation along the Cambodia–Thailand boundary. ASEAN Observer Teams (AOT) deployed under ASEAN procedures observe, verify, and report on cross-border incidents to participating parties.
According to a press release from the Ministry of National Defence dated 2 June 2026, the Cambodian Liaison Group (CLG) facilitated an ASEAN Observer Team led by the Head of Mission (Philippine chair) to inspect the An Ses border checkpoint in Choam Ksan District, Preah Vihear Province at 08:04. The ministry reported that the site has experienced incursions, installation of barbed wire, and the placement of shipping containers by Thai military personnel, which it said continued to prevent some Cambodian families from returning to their homes. The release reiterated Cambodia’s commitment to implement the Joint Statement of the 3rd Special Meeting of the General Border Committee (GBC) dated 27 December 2025 and related agreements, and called for prompt JBC demarcation work in line with those instruments.
Institutional Role
The Ministry of National Defence functions as Cambodia’s authoritative channel for reporting security incidents along the land boundary and for coordinating liaison activities through the CLG. The General Border Committee (GBC) provides a political framework for special meetings and joint statements between Cambodia and Thailand, while the JBC is the technical body tasked with surveying and marking the boundary on the ground.
Key Developments
On 2 June 2026, the CLG hosted the ASEAN Observer Team visit to An Ses to observe, verify, and report on the situation and on compliance with measures set out after a ceasefire. The ministry’s statement specifically referenced physical barriers and container placements at the checkpoint and cited ongoing impediments to civilian return, and it referenced the Joint Declaration on the Peace Agreement (26 October 2025) and the GBC joint statement (27 December 2025) as the basis for resumed normalization and demarcation work.
Operational Implications
The ministry’s public report framed timely commencement of JBC land demarcation as a necessary step to enable safe and dignified return of affected civilians and to restore normal border management. The AOT inspection and the ministry’s reaffirmation of commitments signal continued reliance on bilateral technical mechanisms (JBC) and regional observation (ASEAN) to manage and verify cross-border incidents.
Official Source
Source: Press release, Ministry of National Defence, Kingdom of Cambodia, 2 June 2026; original post at the Ministry’s official social media and website as cited in the source URL.
