Beijing also suggested that the United Nations could consider easing sanctions if North Korea fulfils its obligations under resolutions that punished Pyongyang for its nuclear and missile tests.

The fact that the two leaders "can sit together and have equal talks has important and positive meaning, and is creating a new history," Chinese Foreign Minister Wang Yi told reporters.

"The crux of the peninsula nuclear issue is a security issue. The most important, difficult part of this security issue is for the United States and North Korea to sit down to find a way to resolution via equal talks," Wang said.

"Resolving the nuclear issue, on the one hand of course is denuclearisation, full denuclearisation. At the same time, there needs to be a peace mechanism for the peninsula, to resolve North Korea's reasonable security concerns."

Foreign ministry spokesman Geng Shuang called on the UN Security Council to "make efforts to support the current diplomatic dialogue, efforts to denuclearise the peninsula, and promoting the process of a political settlement of the Korean peninsula issue."

Easing sanctions on Pyongyang, Geng implied, could be one area for the organisation to explore, noting that the "relevant resolutions" provided for the easing of the penalties "in accordance with the compliance of... (North Korea) and the development of the situation".

Beijing is Pyongyang's sole major ally and main trading partner, but it has backed the UN sanctions.

Despite tensions, the Cold War-era allies have sought to mend ties recently, and Kim borrowed an Air China plane to travel to the landmark summit in Singapore.