NEW YORK -- Chinese President Xi Jinping opened his first phone call with new Japanese Prime Minister Fumio Kishida on Friday by citing an ancient Chinese writing.

"Good neighborliness is a treasure of a country," Xi said, borrowing from "The Commentary of Zuo."

The two men agreed to seek "constructive and stable" relations and even engaged in polite small talk -- such as Xi congratulating Japan on successfully hosting the Summer Olympics and welcoming it to take an active part in the upcoming Winter Olympics in Beijing.

The call came after Kishida's inaugural policy speech to the Japanese diet the same day. In it, Kishida said: "Building a stable relationship with China is important for both countries and for the region and the international community." Japan will cooperate with like-minded countries to "say what needs to be said," the prime minister said.

The use of the word "building" hinted at an intention of actively working toward achieving such a stable relationship and differed from his immediate predecessor, Yoshihide Suga, who merely noted in his inaugural policy speech that "a stable relationship with China is extremely important."

In his final policy speech to parliament in January 2020, then-Prime Minister Shinzo Abe said that Japan and China "together share a major responsibility" for the peace and prosperity of the region and the world.

Beijing took Kishida's speech as a positive sign and agreed to go ahead with the telephone call, which lasted 30 minutes.

For good measure, the call came before Kishida talked with Indian Prime Minister Narendra Modi. Kishida had already talked with U.S. President Joe Biden and Australian Prime Minister Scott Morrison on Tuesday. Tokyo avoided looking as if Kishida had consulted with all three of the other Quad partners before engaging with Xi.

Such subtle signaling is giving Beijing hope that Kishida may be a leader it can do business with, despite his hard-line statements as a candidate in the ruling Liberal Democratic Party's presidential race.

China "appreciates" the importance the new Japanese government attaches to maintaining high-level communication between the two countries, Xinhua reported Xi as telling Kishida.

Xi noted that the two sides should strictly observe "the principles set out in the four political documents" between China and Japan and adhere to the position that the two sides are "cooperative partners and not threats to each other."

Since Xi came to power in 2012 as general secretary of the Communist Party, the two countries have never had cozy relations. In his first handshake with Abe in November 2014, on the sidelines of the Asia-Pacific Economic Cooperation summit in Beijing, Xi famously avoided eye contact with the Japanese leader and maintained a sulky expression.

Chinaese President Xi Jinping, right, shakes hands with then-Japanese Prime Minister Shinzo Abe with a stern face during their meeting at the Great Hall of the People in Beijing on Nov. 10, 2014.   © Reuters

While he softened up in later encounters, Xi has never made an official visit to Japan as president, except to attend the Group of 20 summit in Osaka in 2019.

For China, the new neighbor could be the leader it has long been waiting for.

In an interview with Nikkei Asia in 2015, influential Chinese scholar Yan Xuetong, dean of the Institute of Modern International Relations at Tsinghua University, lamented the state of bilateral relations with Japan.

"Japan is the most important country in the region for China," he said. "Japan is more important than Russia. But Japan has the worst relationship with China."

"China really needs to turn Japan into a friendly country. If we can make Japan into a friendly country, our international environment will change dramatically. The problem is that it is very difficult. The Chinese government does not have the confidence to make the [Shinzo] Abe administration friendly toward China," Yan said.

Can Beijing have more confidence with Kishida?

In an interview with Nikkei during the LDP race, Kishida said dealing with China would be a top priority in his government. He expressed "deep alarm" at Beijing's aggressive behavior on the diplomatic and economic fronts and vowed to work with like-minded countries to protect "basic values such as freedom, democracy, the rule of law and human rights" and stand against authoritarian systems.

But these generic punches are acceptable to China and considered different from issues Beijing considers "core interests" -- such as the continuation of Communist Party rule, and territorial issues like Tibet, Xinjiang and Taiwan.

The Xi-Kishida call comes amid a flurry of diplomatic activity by Beijing that is connected to U.S.-China diplomacy. On Wednesday, China's top diplomat, Yang Jiechi, met with Biden's national security adviser, Jake Sullivan, in Zurich, where they agreed to hold a virtual summit between Xi and Biden by the end of the year.

The date of such an online meeting has not been announced. Yet some analysts say it could happen earlier than expected, either before the Oct. 30-31 Group of 20 in Rome, or the Oct. 31-Nov. 12 U.N. Climate Change Conference (COP26) in Glasgow.

Neil Thomas, an analyst for China and Northeast Asia at Eurasia Group, said: "If the virtual summit occurs before one or both of those meetings, trying to improve the chances of success at those summits, it will be a good sign that there's a higher probability of meaningful cooperation between the U.S. and China and the rest of the world on international economic and climate issues."

The hawkish Chinese tabloid Global Times introduced the views of multiple Chinese commentators Friday who expressed optimism over Kishida. They echoed Xi in noting that as long as the "four documents" between the two countries are upheld, the relationship should be stable.

The four documents are the 1972 joint statement that normalized relations after then-Prime Minister Kakuei Tanaka's visit to China; the peace treaty signed in 1978; the joint declaration of 1998, in which the two countries promised annual visits; and the 2008 joint statement that vowed to create a new era of a "mutually beneficial relationship based on common strategic interests."

The fact that Xi largely held off from criticizing Japanese behavior and pointed to the four documents signaled a desire to start anew with Kishida.

The mention of the documents also hint at his first visit to Japan, currently postponed by the pandemic, in which the two sides are considering signing a fifth political document that will define the relationship and give Xi a historic document that he can count as part of his legacy.