HANOI, Vietnam (AP) — Activists and Vietnam War veterans wrapped up a global conference on Agent Orange March 29 with a plea to the U.S. government and chemical companies to take responsibility for health problems linked to the wartime defoliant.

“We … demand that U.S. chemical companies pay compensation equal to their liability. We demand the U.S. government be held responsible for making contributions to overcome the consequences of toxic chemicals,” a statement adopted at the end of the meeting read.

More than 100 activists from at least six countries, including the United States, South Korea, Australia, New Zealand and Canada, attended the two-day conference in Hanoi.

Vietnam has said U.S. aircraft sprayed about 21 million gallons of defoliant, mostly Agent Orange, over Vietnam from 1961-71 to destroy forest cover for communist troops.

Agent Orange contains dioxin, a chemical blamed for health problems ranging from cancer to spina bifida and diabetes. The U.S. government claims there is no scientific evidence directly linking dioxin to the ailments.

A U.S. federal district court in Brooklyn last year dismissed a class-action lawsuit filed on behalf of Vietnamese citizens who claimed that U.S. chemical companies committed war crimes by making Agent Orange for use during the war.

The judge ruled the plaintiffs could not prove that the defoliant had caused their illnesses and that the use of such chemicals did not constitute war crimes.

Tran Xuan Thu, head of the Vietnam Association of Agent Orange Victims, said the conference and public support around the world would help them in their appeal.

“For the future of mankind, we must prevent the use of Agent Orange from being repeated in any other country in the world,” he said.

A large delegation of war veterans from several countries spent a day touring the so-called Friendship Village outside Hanoi where children believed harmed by Agent Orange live.

About 30 veterans spent the morning playing with children at the facility, many of whom are physically or mentally disabled.

Joan Newberry of Santa Fe, N.M., who served as a nurse in the U.S. Air Force during the war, said the conference was a good start to help Agent Orange victims around the world.

“We hope we can develop international alliances that will strengthen our efforts to seek justice for victims of Agent Orange all over the world,” she said.