HO CHI MINH CITY (AFP) - The toxic legacy of the Vietnam War will come under the spotlight again on Wednesday when United States Defence Secretary Jim Mattis visits a former storage site for Agent Orange, which is blamed for birth defects and cancers among a million Vietnamese.
US forces used what is now the Bien Hoa Airport outside Ho Chi Minh City as one of the main staging grounds for storing and deploying the poisonous defoliant that is feared to have seeped into groundwater, rivers and the local food chain.
A carcinogenic dioxin by-product of Agent Orange has affected multiple generations in Vietnam, most visibly in children whose severe mental and physical disabilities - from enlarged heads to deformed limbs - have been linked to the chemical.
Under a 10-year remediation effort led by development agency USAID, work is set to start next year on cleaning up the site that Mr Mattis will visit on Wednesday on his two-day tour of Ho Chi Minh City, the former capital of the US-backed southern regime.
"I just want to get eyes on it so when I go back and I talk to Congress, I can tell them my impression with actually having seen the site," Mr Mattis told reporters as he headed to Vietnam.
The pledge to clean up the site came under the administration of former president Barack Obama, and will cost some US$390 million (S$536 million), officials said.
"We had promised to help... so this is America keeping her promise to remediate some of the past," added Mr Mattis, whose older brother served in Vietnam during the war.
US forces sprayed 80 million litres of Agent Orange over South Vietnam between 1962 and 1971 in a desperate bid to flush out Viet Cong communist guerrillas by depriving them of tree cover and food.
Operation Pacer Ivy
Under a 1972 operation called Pacer Ivy, the US military began pulling Agent Orange from Vietnam for storage and disposal outside the country.
The site Mr Mattis is inspecting was used in that operation, a US defence official said, noting that it is now quarantined.
Mr Chuck Searcy, a US veteran who served in Vietnam in 1967 and 1968, and now lives in Hanoi, said he was happy Mr Mattis was going to Bien Hoa and hoped it would lead to more funding for the dioxin clean up.
"His visit is important because it reflects a commitment on the part of the Department of Defence to be involved with this issue in a positive way," said Mr Searcy, who works with Project Renew which clears unexploded ordnance in Vietnam.
"A lot of us have been waiting for that to happen for quite a long time, so this is encouraging," he told AFP.
Ties between the former foes have warmed considerably since the end of the war and Washington is one of Hanoi's most important political and military allies and trading partners.
It is Mr Mattis' second trip to Vietnam this year after a trip in January, which was followed by a historic visit by a US aircraft carrier in March, the first to Vietnam's shores since the war, in a symbolic burying of the hatchet for both sides.
In addition to Bien Hoa, the US and Vietnamese have identified two other "dioxin hotspots" - Danang and Phu Cat airbases. A project to clean up Danang is nearly complete.
Hanoi says up to three million Vietnamese people were exposed to Agent Orange, and that one million suffer grave health repercussions today, including at least 150,000 children with birth defects.
An attempt by Vietnamese victims to obtain compensation from the US had little success, and the US Supreme Court in 2009 declined to take up the case.
American veterans have received billions of dollars for diseases linked to Agent Orange but neither the US government nor the chemical manufacturers ever admitted liability, and some say the US has not done enough.
"It's never enough. The US has been quite slow in this matter... The victims of Agent Orange must be cared for and given support to overcome their hardships," said Mr Pham Chuong from the Vietnamese Association of Victims of Agent Orange.