The Mekong River has become a new front in the U.S.-China rivalry, environmentalists and officials say, with Beijing overtaking Washington in both spending and influence over downstream countries at the mercy of its control of the river¡¯s waters.

It¡¯s a confrontation in which the administration of U.S. President Donald Trump ¡ª which has largely maintained funding for Barack Obama-era environmental and development programs in the Lower Mekong ¡ª is losing ground.

The two powers¡¯ struggle recently moved into the realm of science ¡ª with the U.S. and Chinese governments each touting different reports about whether China¡¯s 11 dams on the river were harming nations downstream.