China's top diplomat hinted Wednesday to former American secretary of state Henry Kissinger, the 100-year-old who was at the heart of the United States' rapprochement with China half a century ago, that Beijing was nostalgic for the days he was running U.S. foreign policy.

Kissinger is on an unannounced visit to Beijing that coincides with that by another former American secretary of state: John F. Kerry, now the Biden administration's climate envoy, is in Beijing for talks aimed at kick-starting cooperation between the world's two biggest polluters.

It also comes on the heels of current Secretary of State Antony Blinken's trip to Beijing last month, when both sides projected positivity after six months of verbal confrontation and military near misses.

But neither has the stature of Kissinger, who remains revered in China for his efforts to forge diplomatic relations between the two countries.

Kissinger secretly visited Beijing in 1971 to lay the groundwork for President Richard M. Nixon's historic trip the following year, which led to rapprochement with China. The two countries official recognized each other in 1979.

On Wednesday, Wang Yi, China's former foreign minister and now its top diplomat, greeted Kissinger, who was using a walking stick, in Beijing.

"It is impossible to try to transform China, and it is even more impossible to contain China," Wang told the American, according to a Chinese report of the meeting. "U.S. policy toward China requires the diplomatic wisdom of Kissinger and the political courage of Nixon," Wang reportedly said.

This came a day after Kissinger met Chinese Defense Minister Li Shangfu, according to a report by the official Xinhua News Agency that was also posted on the ministry's website.

Military communications in particular are so fraught that Li refused to meet with U.S. Defense Secretary Lloyd Austin at a regional security forum in Singapore last month.

Also in June, Blinken tried to get an agreement to resume direct military-to-military communications between the United States and China. But, he said, Beijing rejected the idea despite dangerous recent near misses.

Yet in Beijing on Tuesday, Li told Kissinger that he hoped the United States will "work with China to implement the consensus reached by the leaders of the two countries and promote the healthy and stable development of relations between the two countries and their militaries," Xinhua said.

Li has been under U.S. sanctions since 2018 over China's purchase of combat aircraft and equipment from Russia's main arms exporter.

Kissinger responded that both the United States and China should eliminate misunderstandings, Xinhua reported.

"History and practice have repeatedly proven that neither the U.S. nor China can afford the cost of treating each other as opponents," Kissinger said, according to the Chinese account. "If the two countries go to war, it will not bring any meaningful results to the people of the two countries."

The State Department was aware that Kissinger was traveling to China, spokesman Matthew Miller told reporters in Washington on Tuesday.

"It actually came up in the meetings that Secretary Blinken had when we were in China," Miller said. "The Chinese officials mentioned that he was planning to come, as he has done a number of times over the years as a private citizen. I will say he was there under his own volition, not acting on behalf of the United States Government."