More than 80 years after Chinese and American forces stood side by side against Japanese aggression in World War II, that legacy of shared struggle came to the fore in Washington on Thursday as the two countries' leaders honored the bond forged in war.

As U.S. President Donald Trump welcomed Chinese President Xi Jinping to the White House on Thursday morning, the shadow of the wartime history gave way to shared memory -- with Xi recalling how the two peoples once stood shoulder to shoulder against fascist aggression.

Invoking a shared historic legacy, Xi reflected on the deep ties forged during wartime.

"During the Second World War, Chinese and Americans fought shoulder to shoulder against fascist aggression. Chinese people have never forgotten that part of history, nor have the American people," Xi said.

Trump brought back the shared wartime memory by recalling the history of the U.S. and China fighting alongside each other as allies during World War II. "Throughout history, the pursuit of those common interests has connected our people across vast oceans, those big, tremendous distances and many differences, and even made us allies in World War II," he said.

Trump praised the Flying Tigers, officially known as the American Volunteer Group of the Chinese Air Force, for those American pilots' bravery during their joint combat with Chinese soldiers and civilians against the Japanese invasion.

Trump noted that "it was the United States Marines' encounter with Chinese people that inspired the Marines to adopt a Chinese phrase they still use today, 'gung ho.'"

"The Marines use it as an expression of great enthusiasm, but in Chinese, it literally means working together," Trump said.

The term "gung ho" originated from the Chinese Industrial Cooperatives movement, also known as the "Gung Ho" movement, launched in the late 1930s to support China's war effort.

"Just as our people worked together to win that war, President Xi and I will continue working together to forge a better future for both of our nations," he added.

At a state dinner hosted by Trump on Thursday evening, Xi took a moment to recount the story of the Hump Route.

"Over 80 years ago, the Chinese and American people stood shoulder to shoulder in the fight against Japanese militarist aggressors. Together we opened the famous Hump air route over the Himalayas. During the War of Resistance Against Japanese Aggression, Chinese soldiers and civilians rescued hundreds of American pilots at the cost of hundreds of thousands of Chinese lives," Xi said.

The Flying Tigers helped open and safeguard the Hump Route, a vital air corridor over the Himalayas that became a wartime lifeline for China. From 1942 to 1945, the route served as a key channel for Allied supplies to support China's resistance against Japanese aggression.

This focus on wartime alliance came right on the heels of Japanese Prime Minister Sanae Takaichi's meeting with Trump at the United Nations General Assembly in New York two days earlier.