Agent Orange cleanup starts

The project will focus on dioxin contamination at Bien Hoa airport on the outskirts of southern Ho Chi Minh City. It is one of three former American air bases where U.S. forces mixed, stored and loaded the defoliant onto planes for spraying missions during the Vietnam War to destroy jungle hideouts of enemy Communist forces, according to the Associated Press.

Between 1962 and 1971, the U.S. military sprayed roughly 11 million gallons (41 million liters) of Agent Orange across large swaths of southern Vietnam. Dioxin is a toxic chemical used in the herbicide that has been linked to cancers, birth defects and other ailments.

"Without action, the hotspots will continue to contaminate the wider environment and pose a serious health risk to people living and working nearby," the U.N. Development Program statement said.

Vietnam says as many as 4 million of its citizens were exposed to the herbicide and as many as 3 million have suffered illnesses caused by it, but the United States says there is no scientific evidence to link Agent Orange to the illnesses.

Since 2007, the U.S. Congress has approved $9 million relating to Agent Orange in Vietnam, mostly to address environmental cleanup. Earlier this month, a joint U.S.-Vietnam working group of private citizens, policymakers and scientists called for $300 million over 10 years to decontaminate sites and provide treatment to Vietnamese with disabilities, including those believed related to dioxin exposure.

The plan asks the U.S. government to help fund a substantial portion of the project. The Agent Orange issue remains the most contentious legacy between Vietnam and the U.S. since the war ended 35 years ago.