BEIJING - The foreign minister of North Korea's chief ally China will visit Pyongyang this week following the historic summit between the leaders of the two Koreas.

The trip by Wang Yi comes as Beijing and Pyongyang continue an effort to repair ties that have suffered from tensions in recent years, and ahead of a planned meeting between U.S. President Donald Trump and the North's leader Kim Jong Un.

Foreign ministry spokesman Lu Kang said in a statement issued Monday that Wang will visit on Wednesday and Thursday.

China is the North's only major economic partner, but trade has declined by about 90 per cent following Beijing's implementation of economic sanctions imposed over the North's nuclear bomb and ballistic missile tests.

Kim last month made his first visit to Beijing since taking power six years ago, kicking off a flurry of diplomacy highlighted by his meeting with South Korean President Moon Jae-in last week. South Korean officials said Kim told Moon that he would be willing to give up his nuclear weapons if the U.S. commits to a formal end to the Korean War and a pledge not to attack the North.

Kim also pledged to shut down the North's nuclear test site in May and disclose the process to experts and journalists from South Korea and the United States, Seoul's presidential office said.

China has long called for dialogue between the parties and welcomed the summit as a vehicle for reducing tensions. Analysts say China's sanctions implementation may have helped prompt the North's diplomatic initiatives although the secretive regime in Pyongyang has made no public comments on the issue.

China says sanctions are intended to further diplomacy rather than punish the North and opposes any measures that could topple the regime, possibly bringing a tide of refugees across its border and leading to the stationing of U.S. and South Korea troops in the North.