The Operational Structure of ACMECS: How Mekong Countries Drive Cooperation

The Operational Structure of ACMECS: How Mekong Countries Drive Cooperation

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Key Insights

• ACMECS was established in 2003 to strengthen economic competitiveness and narrow development gaps among the five Mekong countries.
• The framework operates through multi-layered coordination, connecting political leadership with technical implementation.
• Three strategic pillars—Seamless, Synchronized, and Smart & Sustainable ACMECS—guide regional cooperation under the Master Plan 2019–2023.
• Decision-making is driven by the rotating Chairmanship, Leaders’ Summit, Senior Officials’ Meeting, and Coordinating Committee.
• Each cooperation area has a sector-leading country responsible for advancing projects through specialized working groups.
• The ACMECS Interim Secretariat established in 2024 strengthens coordination, planning, communication, and project management.
• ACMECS enhances regional resilience in a multipolar world by serving as a Mekong-driven platform that complements ASEAN and engages major development partners.

The Ayeyawady–Chao Phraya–Mekong Economic Cooperation Strategy, widely known as ACMECS, is one of mainland Southeast Asia’s most important Mekong subregional cooperation frameworks. Bringing together Cambodia, Lao PDR, Myanmar, Viet Nam, and Thailand, ACMECS aims to enhance economic competitiveness, narrow development gaps, and promote shared prosperity in the Mekong subregion. While its goals are widely recognized, many still wonder: How does ACMECS actually work? Who makes the decisions? And what mechanisms turn Mekong subregional aspirations into actions?

This article explains the origins, cooperation pillars, working mechanisms, and decision-making structure of ACMECS, highlighting how member countries coordinate across multiple levels to create practical benefits for the subregion.

The Establishment of ACMECS

From the beginning, since its establishment in 2003, ACMECS has been deeply rooted in the larger Mekong cooperation landscape. As a Mekong-centric framework driven by the five riparian countries themselves, ACMECS complements subregional and regional efforts including the aspiration of the Mekong River Commission (MRC), and the ASEAN integration. It also encourages constructive engagement with Development Partners (DPs) such as Australia, China, India, Japan, the Republic of Korea, the United States, and most recently New Zealand.

The ACMECS Master Plan

A major milestone came on 16 June 2018, when the 8^th ACMECS Summit in Bangkok adopted the ACMECS Master Plan 2019–2023. The Plan restructured cooperation into three strategic pillars:

1. Seamless ACMECS: Focusing on physical connectivity, including transport infrastructure, cross-border linkages, logistics routes, tourism corridors, as well as digital and energy infrastructure.
2. Synchronized ACMECS: Targeting “soft connectivity” through harmonized regulations, investment frameworks, industrial cooperation, digital trade, and financial facilitation.
3. Smart and Sustainable ACMECS: Promoting sustainability, human capital development, technology transfer, and the continuation of existing cooperation sectors, particularly agriculture, public health, tourism, and the environment.

These pillars guide all policy-level and technical work, ensuring that ACMECS remains relevant to both development opportunities and regional challenges.

How ACMECS Works: The Operational and Decision-Making Structure

ACMECS operates through multiple layers of endavours that connect political commitment with technical execution. Each level plays a different but complementary role.

           The ACMECS Chairmanship: the ACMECS Chair rotates among the five member countries, typically on a two-year cycle. The Chair is responsible for setting annual priorities, hosting key meetings, and leading negotiations. The Chair acts as a political anchor, ensuring momentum and continuity in subregional cooperation.

             Senior Officials’ Meeting (SOM): The Senior Officials’ Meeting is the backbone of ACMECS. Senior officials from foreign ministries, line ministries, and relevant agencies: SOM review cooperation progress, harmonize national positions, draft policy recommendations, and prepare documents for ministerial or summit endorsement. SOM is where most negotiation, data analysis, and planning occur. Officials work closely with technical working groups, who operate “in the field” to gather information, and evaluate challenges.

            Coordinating Committee: ACMECS comprises of 3 Coordinating Committees playing role in driving cooperation under 3 pillars of ACMECS Masterplan 2019-2023. The mechanisms ensure that sectoral work moves forward smoothly, linking the demands of the ACMECS member countries, sector-leading countries, technical agencies, and the interim Secretariat. This Committee is essential for synchronizing project timelines, mobilizing resources, and drafting long-term strategies such as the ACMECS Master Plan.

            The Summit: The Summit, held every two years, is ACMECS’s highest decision-making body to setting political direction. At this level: Heads of Governments endorse political declarations, approve long-term strategies, provide mandates for cooperation priorities, and give momentum to emerging issues. Examples include: The 7^th ACMECS Summit (2016) adopted the Hanoi Declaration, emphasizing a dynamic and prosperous Mekong subregion aligned with the Sustainable Development Goals (SDGs). The 9^th  ACMECS Summit (2020) highlighted post-COVID-19 economic recovery, vaccine cooperation, and support for MSMEs. The 10^th ACMECS Summit (2024) in Vientiane accelerated the establishment of the ACMECS Development Fund (ACMDF) and welcomed New Zealand as the newest ACMECS Development Partner. Summits therefore serve as the political compass that directs all works of ACMECS.

            ACMECS Interim Secretariat A significant institutional reform occurred in 2024, when member countries agreed to establish the ACMECS Interim Secretariat in Bangkok. Its four core mandates are: Policy planning and coordination, Meeting services, Project management, Strategic communication.

Why ACMECS Matters in Today’s World

Consisting solely of Mekong countries, ACMECS provides a Mekong-driven platform that sets subregional agendas and defines clear entry points for engagement with Development Partners. It also serves as a strategic connector within an increasingly crowded landscape of Mekong cooperation frameworks, helping to strengthen collective resilience and regional autonomy. This strong internal cohesion gives ACMECS a distinct advantage, it not only aligns national policies and priorities among its member countries, but also guides the focus and modalities of cooperation with external and development partners.

As Mekong countries confront interconnected challenges, ranging from water resources management and water contamination to transboundary crimes and online scams, transboundary air pollution, public health emergencies, and intensifying major-power competition, ACMECS offers Development Partners a clear, demand-driven framework for engagement. This helps ensure that external support complements, rather than fragments, ongoing subregional efforts. By reinforcing Mekong ownership while remaining open and inclusive, ACMECS enhances its members’ ability to navigate global uncertainty, leveraging cooperation with Development Partners to advance shared subregional priorities while safeguarding long-term stability, solidarity, and sustainable development.

ACMECS: A multi-layered operational system

ACMECS is more than a political statement; it is a multi-layered operational system that connects leaders’ political vision with practical action on the ground. Through its Chairmanship, Summit, Senior Officials’ Meetings, Coordinating Committee, sector-leading countries, and the Interim Secretariat, ACMECS has built a coherent structure capable of driving subregional cooperation.

Understanding this structure is essential for appreciating how Mekong countries—linked by geography, culture, and shared challenges—work together to build a dynamic, interconnected, and sustainable subregion. As global uncertainty grows, ACMECS’s role as a Mekong-centric cooperation framework becomes even more vital—not only for economic development but also for strengthening regional stability, solidarity, and long-term resilience.