China's vice president told North Korean leader Kim Jong-un that Beijing will push for talks on ridding the Korean peninsula of nuclear weapons, as he led a delegation to Pyongyang to mark the 60th anniversary of the end of the Korean War.

Li Yuanchao is a member of China's 25-member Politburo and the talks are the highest-level contact between China and North Korea since Kim assumed power in December 2011 upon the death of his father, Kim Jong-il.

Li conveyed a "verbal message" from Chinese President Xi Jinping to Kim during the meeting on Thursday, China's Foreign Ministry said in a statement issued on Friday.

"As a close neighbour of the Korean peninsula, China will persist in the denuclearisation of the peninsula, adhere to safeguarding the peace and stability on the peninsula and persist in using dialogue and consultation to resolve the problem," Li was quoted as telling Kim.

Li reiterated that China was willing to work with all concerned parties to promote six-party talks and was "committed to pushing for the process of denuclearisation".

Six-party aid-for-disarmament talks, involving the two Koreas, the United States, Japan, Russia and host China, collapsed in 2008 when the North walked out.

Kim told Li that North Korea "supports China's efforts to resume the six-party talks", according to China's Foreign Ministry.

China is the main economic and diplomatic lifeline for impoverished and isolated North Korea, which has tested nuclear weapons three times since 2006, and the neighbours have shared adversity in the past.

Visiting the graves of Chinese soldiers killed in the Korean War, Li praised their sacrifice in the name of "defending peace and protecting justice", China's Xinhua news agency reported.

"The reason we are commemorating the 60th anniversary of the end of the Korean War is to look forward to the future, to better maintain peace and stability on the Korean peninsula and seek regional prosperity and development," Li added.

China has grown increasingly frustrated with North Korea since it conducted its latest nuclear test in February.

The North threatened South Korea and the United States with nuclear war for weeks in response to toughened U.N. sanctions imposed after the test, but it has since been more conciliatory.

Li told Kim that relations between China and North Korea were "entering a new era" and they would build on the past while preparing for the future, China's Foreign Ministry said. Li's visit ends on Sunday.

In June, a top North Korean diplomat repeated an offer for international talks on his country's nuclear programme during a meeting in China, saying the denuclearisation of the peninsula was the "dying wish" of North Korea's founder, Kim Il-sung.

The United States has said any talks must involve action by the North to show it is moving toward disarmament.

Washington has been sceptical of moves by Pyongyang towards dialogue as it has repeatedly backtracked on deals, most recently in 2012, when it agreed to a missile and nuclear test moratorium only to fire a rocket a few weeks later.