Laos has told Vietnam it will suspend work on a controversial dam planned for the Mekong River, official media reported, after Hanoi sought a 10-year deferment of the scheme.
Lao Prime Minister Thongsing Thammavong informed his counterpart Nguyen Tan Dung "of Laos' decision to temporarily suspend the Xayaburi hydropower project," Vietnam News Agency (VNA) reported at the weekend from Jakarta.
It said the two communist leaders met in the Indonesian capital on the sidelines of the ASEAN regional summit.
"PM Dung thanked the Lao Party and government for this important decision", which reflected "deep consideration" of Vietnam's position, the VNA report said.
At a regional meeting last month, Vietnam, which has close political ties with tiny, landlocked Laos, voiced "deep" concerns about inadequate assessments and the risk of damage to its fishing and farm industries.
It called for hydropower projects on the mainstream Mekong to be deferred for at least a decade.
Workers had already begun building roads to the site in northern Laos. Xayaburi is the first of 11 such projects proposed for the mainstream lower Mekong.
"We are glad that the Lao government considered the postponement of this project and commission of a new study... due to strong and wide opposition," said Pianporn Deetes, a spokeswoman in Bangkok for the US-based environmental group International Rivers.
While welcoming the announcement from Vietnam, she said Laos should issue its own statement.
Environmentalists have warned that damming the lower Mekong would trap vital nutrients, increase algae growth and prevent dozens of species of migratory fish -- including the giant catfish -- swimming upstream to spawning grounds.
Laos, Vietnam, Thailand and Cambodia make up the Mekong River Commission (MRC), an inter-governmental body that deals with all Mekong River-related activities including fisheries, agriculture and flood management.
Laos had not yet informed the MRC secretariat of a formal suspension of the project but "Vietnamese authorities have confirmed the news report".
"We are still waiting for a response from the Lao authorities," the secretariat told AFP in a statement.
More than 60 million people in the lower Mekong basin depend on the river system for food, transport and economic activity, the MRC says.
Laos is one of the poorest countries in the world and sees hydropower as vital to its future.
Explore further: How tropical subsoil microbes could affect the carbon cycle