The U.S. ambassador to Vietnam, Michael Marine, has announced that the U.S. is giving Vietnam $400,000 toward an Agent Orange clean-up.
The money will help pay for a $1 million study of ways to remove dioxin from contaminated soil at a former U.S. base at Danang.
Agent Orange is a toxic defoliant sprayed by the U.S. military during the Vietnam War to strip jungle cover.
The Vietnam government blames its use for a range of diseases and birth defects in the country.
Hanoi has asked for compensation. However, Washington says there is no proven scientific link between Agent Orange and health problems.
The Vietnam War ended in April 1975.
A Vietnamese victims group sued 37 U.S. chemical companies that made Agent Orange, but the lawsuit was thrown out in 2005. The group is appealing the ruling.
Some information for this report was provided by AP and Reuters.