So far, Vietnam and the US have conducted more than 4,000 joint investigations, with 1,000 missing military remains being handed over to the US. The two sides are continuing to coordinate in searching for 200,000 Vietnamese martyrs and Vietnamese soldiers missing in the war. In photo: The reception of four US soldiers' remains at Noi Bai International Airport in Hanoi in the presence of US Secretary of State Warren Christopher, August 5, 1995 (Photo: VNA)

Deputy Defense Minister Nguyen Chi Vinh and Deputy Assistant Secretary of Defense for South Asia and Southeast Asia Amy Searight co-chair the Vietnam-US Defense Dialogue in Hanoi, October 21, 2014 (Photo: VNA)

Signing ceremony of a memorandum of intent between the Military Science Department, the Ministry of Defense of Vietnam and the United States Agency for International Development (USAID) on dioxin remediation in Bien Hoa airport area in Vietnam, January 23, 2018 (Photo: VNA)

Minister of Defense Ngo Xuan Lich receives a delegation of US Senators, led by Senator Patrick Leahy, Vice Chairman of the US Senate Standards Committee during a working visit to Vietnam, April 18, 2019 (Photo: VNA)

Permanent Deputy Prime Minister Truong Hoa Binh and Senator Patrick Leahy, US Ambassador to Vietnam Daniel Kritenbrink and delegates at launching ceremony of the Bien Hoa Airport Dioxin Contamination Treatment Project (Photo: VNA)

US Defense Secretary Leon Panetta presents to Vietnam's Defense Minister diary books of Vietnamese soldiers during war, June 4, 2012 (Photo: VNA)

Deputy Defense Minister Nguyen Chi Vinh meets with Chairman of the US Joint Chiefs of Staff Martin Dempsey on the sidelines of the 13th Asian Security Summit - Shangri-La Dialogue in Singapore, May 31, 2014 (Photo: VNA)

Deputy Minister of Defense Nguyen Chi Vinh works with Assistant Secretary of Defense Puneet Talwar during his visit to the United States from March 23 - 24, 2015 (Photo: VNA)