The summit in Singapore “is a major step in the political process to resolve nuclear issues on the Korean peninsula”, Xi was quoted as saying by state broadcaster CCTV.

“Chairman Kim has made positive efforts to safeguard peace on the peninsula,” he said. “[I] hope both North Korea and the US can carry out the outcomes of the leaders’ summit and … work together to push forward the peace process.”

The North Korean leader was quoted as saying he appreciated Beijing’s support.

Xi and his wife, Peng Liyuan, welcomed Kim and his wife, Ri Sol-ju, at a red carpet ceremony at the Great Hall of the People in Beijing, before joining other Chinese leaders for a banquet.

At their face-to-face meeting last week, Kim and Trump signed a vaguely worded statement pledging to push ahead with the “complete denuclearisation” of the Korean peninsula. US Secretary of State Mike Pompeo said on Tuesday he was likely to visit Pyongyang again soon as the two sides continued to work on the issues discussed in Singapore.

South Korea and the US have also agreed to suspend a joint military exercise planned for August, in a move the Pentagon said was in line with the pledges made by Trump and Kim.

Cheng Xiaohe, an associate professor of international relations at Renmin University, said that while Kim had been expected to visit Beijing to brief Xi on the outcome of the Singapore summit, the fact it was his third visit in such a short time signalled how significant the meeting had been.

“It is unprecedented for a foreign leader to visit China three times in three months, but the unusual arrangement [reflects] it is a special moment for the Korean peninsula,” he said.

Kim was also likely seeking Beijing’s support and guidance, Cheng said.

“Apparently it was Washington that made the concessions in Singapore, so now it’s Pyongyang’s turn to make a move,” he said.

“Kim is likely to seek Beijing’s advice, as well as its support and understanding ahead of the next round of negotiations.”

While Washington has said repeatedly it wants Pyongyang to commit to the comprehensive, verified and irreversible disarmament of the peninsula, the joint declaration signed at the Trump-Kim summit did not include any timelines or specific targets.

Park Ihn-hwi, an international studies professor at Ewha Womans University in Seoul, said North Korea would want economic incentives before committing to complete denuclearisation.

“Kim wants to see a detailed road map for lifting the United Nations sanctions,” he said, adding that Kim’s efforts to restore relations with China was evidence of that.

Go Myong-hyun, a research fellow at the Asan Institute for Policy Studies in Seoul, said Kim’s latest visit might suggest that the North Korean leader was not entirely satisfied with the outcome of the Singapore summit.

“Although Kim was successful in solidifying his legitimacy to rule, he may not be totally happy with the result as there was no mention of easing the sanctions,” he said, adding that Trump had not given up anything at a “practical level”.

“So Kim may ask Xi to ease the UN sanctions imposed against his regime.”

North Korea’s plan to prioritise economic development over nuclear weapons emerged in April, when Kim said he wanted to move away from the byungjin policy, which put the two on a par.

Besides the direct support Xi is giving Kim, China role in future efforts to bring about a peace treaty to formally end the Korean war remains unclear. Neither Washington nor Seoul made any mention of Beijing in recent statements about the issue.

“From a Chinese perspective, its participation in the upcoming [peace] process is natural and inevitable,” Go said.