Qin Gang, Chinese ambassador to the U.S., delivers a speech Saturday at the opening ceremony of a photo expo. The expo was held at the National Air and Space Museum in the U.S. to commemorate the 80th anniversary of the Flying Tigers and America's Second World War Air Defense of China. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

Ambassador Qin chats with guests at the expo wearing a pilot jacket brought by two Flying Tigers aged 101 and 98. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

A Flying Tigers leather jacket on display in China in 2007. The American Volunteer Group, also known as the Flying Tigers, was formed to help fight against the Japanese invasion of China and Southeast Asia during World War II. Photo: VCG

Claire Lee Chennault (left), commander of the Flying Tigers, directs his soldiers in the 1940s. Consisting of former Army, Air Force, and Marine Corps pilots, the group was formed in the summer of 1941 by Chennault. Photo: Corbis/VCG

Chennault inspects airplanes in 1944. In July 1942, the group was disbanded. Later, some of the Flying Tigers formed the 23rd Fighter Group, which was part of the 14th Air Force. Photo: Corbis/VCG

Members of the 23rd Fighter Group pose for a photo in front of their military flag in 1943. Insignia on the flag shows the group’s links with the Flying Tigers. Photo: VCG

Members of the Flying Tigers fly P-40 planes on the Far Eastern front in 1943. Photo: Three Lions/VCG

Ambassador Qin views exhibited photos with guests at the expo on Saturday. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

Norton A. Schwartz, former chief of staff of the United States Air Force, speaks at the expo. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

Charles Bolden, former NASA administrator, said China and the U.S. should work more in fields, like aerospace and climate change. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

Jeffrey Greene, chairman of the Sino-American Aviation Heritage Foundation, speaks at the expo. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America

The exhibition displayed nearly 700 historical photos depicting China and the U.S. working together to fight against Japanese forces during World War II. It launched last year and will later move to New York. Photo: Courtesy of Embassy of the People's Republic of China in the United States of America