The United States has criticized Laos’ decision to build the first dam across the mainstream of the Mekong River. The US has urged a moratorium on such projects until studies into their impacts are completed, but the State Department said on Monday that Laos has announced its intention to start construction on the US $3.5 billion Xayaburi dam despite lingering concerns downstream. Opponents say the dam in central Laos would open the door for a building spree of as many as 10 other dams on the 4,800-km-long river, degrading its fragile ecology and affecting the livelihoods of residents.—AP