NANJING, China — China marked the anniversary of the Nanjing Massacre by Japan with a message of peace and friendship last week, potentially helping to realign relations between the rival Asian powers.

A somber President Xi Jinping led a nationally televised ceremony to remember the estimated 300,000 Chinese who died when Japan’s Imperial Army occupied Nanjing, then China's capital, 80 years ago.

China has consistently reminded its people of the 1937 massacre, but in what is being interpreted as a highly significant diplomatic gesture, Xi did not lay wreaths or speak at the event on Wednesday, as he did on the same occasion three years ago.

Instead, the memorial speech was relegated to a lower-ranking senior party official, Yu Zhengsheng, who called for China and Japan “to grasp the broad direction of peaceful and friendly cooperation ... and pass on friendship from generation to generation.”

A postwar international tribunal put the death toll from the massacre at 142,000, while some conservative Japanese politicians and scholars deny that one took place at all. Ties between China, the world's second-largest economy, and Japan, the third-largest, have also been plagued by a territorial dispute over islets in the East China Sea and suspicion in China about efforts by Japanese Prime Minister Shinzo Abe to amend Japan's pacifist constitution.

Wednesday's conciliatory message, delivered on the occasion of the most brutal episode in Japan’s invasion of China, was not lost on observers.

After years of disputes over history, regional rivalry and even maritime territory, “China is clearly shifting gear and seeking to lower tension and improve ties with Japan,” said Zhang Lifan, a political historian in Beijing.

“As China expands its influence and encounters resistance in the region and beyond, improved relations with Japan can mitigate the situation and help China to focus on more urgent threats like the North Korean nuclear crisis,” he said.

"We have to move on and we still need to deal with Japan, trade with Japan, send students to Japan”

“With President Trump urging Japan to bear more responsibilities, Prime Minister Abe cannot but think of various ways to have a modus vivendi with China,” he added.

China is committed to improving ties with Japan by “taking history as a mirror and looking forward to the future,” Chinese Foreign Ministry spokesman Lu Kang told NBC News when asked about the significance of the Nanjing event.

Others argued, however, that geopolitical self-interest is truly driving the changing dynamic between the regional rivals.

“On the one hand, Abe will follow Trump, as on the North Korean issue," said Shi Yinhong, Dean of the School of International Studies at Beijing’s Renmin University. "But on the other hand, Japan has some doubts about Trump’s policies.”

People participate in a ceremony at the Nanjing Massacre Memorial Hall on the second annual national day of remembrance to commemorate the 80th anniversary of the massacre in Nanjing on Dec. 13, 2017. Chandan Khanna / AFP - Getty Images

“The decisive factor, however, is that conflict is too costly for both sides," added Shi, who supports “new thinking” for better relations between China and Japan.

The diplomatic signaling that emerged from the Nanjing ceremony merely represents “a continuation of a process,” he said, pointing out that the turning point in relations may actually have been Japan's endorsement of the Belt and Road project, Xi’s signature economic program to link Asia with Europe, the Middle East and Africa.

A breakthrough was then apparently achieved in November when the country's two leaders emerged from a meeting on the sideline of a regional summit in Hanoi to declare “a fresh start” in the relationship.

This was followed days later by Abe’s declaration that ties had improved to the point that the two leaders could visit each other’s capital next year.

The momentum led Tokyo and Beijing to agree in early December to establish a maritime hotline to prevent and control accidental clashes in the East China Sea. It has taken 10 years to reach a deal on the issue because of ongoing disputes over a group of uninhabited islands that Japan controls but over which China claims sovereignty.

The issue of forging a friendship with Japan continues to divide Chinese public opinion, however — often over the Nanjing massacre itself.

The executed bodies of Chinese civilians and soldiers cover the ground as Japanese soldiers stand in the background after a battle to take Nanking — now Nanjing — in 1937. Pictures Inc. / The LIFE Picture Collection via Getty Images

“If a friend is someone you can trust, then China and Japan will never be friends,” said Zhang Boyu, 22, a Peking University student from the Northeastern province of Jilin, a region once occupied by Japan.

Another student, Yu Qiran, 21, who attends the Communications University of China, said: “We can be friends as long as they admit what they did and face it. But if someone will not respect history, then I will never be friends with them."

Noting the debate over whether Japan's apology for wartime atrocities is sincere, Yuan Gang, a government professor at Peking University, argued that “history should not be an impediment” to developing relations. “Are you requiring the Japanese to kneel?” he asked, stressing that Japan supported China’s open-door policy and economic reforms.

Bian Weipin, 58, a retired driver and native of Nanjing, shared that sentiment.

“The painful history will always be in our heart," he said. "But we have to move on, and we still need to deal with Japan, trade with Japan, send students to Japan.”