Which of the following countries does NOT consider the Mekong River to be a prinicpal river system?

Vietnam

Myanmar

Cambodia

Laos

The Mekong river is one of the primary landforms in the South-east Asian peninsula wherein it stretches 4,200 km from Southern Cambodia to the north of Myanmar. In addition, the river system has been the source of transportation as well as fisheries in settlements surrounding it. The country where the river is not its primary water system would be Vietnam.