The first meeting of environment ministers from the Greater Mekong Subregion was held in Shanghai in the People's Republic of China on 25 May 2005.

The environment ministers from the six GMS countries, namely, Cambodia, People’s Republic of China, Lao People’s Democratic Republic, Myanmar, Thailand, and Viet Nam, endorsed the launching of the Core Environment Program and the establishment of the Environment Operations Center for its implementation by early 2006.