PHNOM PENH, April 5 (Xinhua) -- The third Mekong River Commission (MRC) Summit was held in northwestern Cambodia's Siem Reap province on Thursday, aiming to promote the sustainable development in the Mekong river basin.

Cambodian Prime Minister Samdech Techo Hun Sen, Thai Prime Minister Prayut Chan-o-cha, Vietnamese Prime Minister Nguyen Xuan Phuc, and Lao Prime Minister Thongloun Sisoulith attended the summit.

High-level representatives from the upper Mekong countries, China and Myanmar, also attended the summit in the status of the MRC's dialogue partners.

Hun Sen said the summit was a historical event and was an important gathering to review the progress and draw up strategic plans for the sustainable development of the Mekong river basin.

"The cooperation under the framework of the MRC has been progressing with a synergy in promoting socio-economic development and improving the sustainable management of water and natural resources in the Mekong river basin," he said in his opening speech.

"Cambodia is committed to working together with all countries along the Mekong River and other partner countries of the MRC in order to further strengthen regional cooperation and partnership for the sustainable development and growth in the Mekong river basis," he said.

Held every four years, the summit was expected to adopt the Siem Reap Declaration to promote the partnership among the four lower Mekong countries on water and natural resources management and the sustainable development of the Mekong river basin.