The man widely expected to be China's next premier arrived in North Korea Sunday, amid hopes for progress on restarting six-nation talks on the North's nuclear disarmament, state media said.

Li Keqiang, China's vice premier, visited the capital Pyongyang the day before the United States and North Korea are due to meet in Geneva for their second round of direct discussions aimed at reviving the long-stalled negotiations.

Li said his visit will help promote resumption of the six-nation talks on the North's nuclear disarmament, according to a statement released by the official Xinhua news agency after his arrival.

"China appreciates the positive efforts of (North Korea) in improving North-South relations... and in promoting the resumption of the six party talks," he said.

China has hosted the forum, which includes the two Koreas, Russia, the United States and Japan, since 2003.

The official visit is scheduled to last until Tuesday, China's foreign ministry said. Li was accompanied by officials from China's foreign and commerce ministries.

China is Pyongyang's closest ally and a major economic partner.

China's Ambassador to North Korea, Liu Hongcai, said the visit would deepen ties and make "positive contributions" to peace and stability in the region, Xinhua reported.

Total trade between the two neighbours surged an annual 87 percent in the first seven months of this year to $3.1 billion, he said in an interview with the agency. North Korea depends on China for oil and food.

Afterwards Li, likely to take over from current Premier Wen Jiabao in 2013, is due to visit South Korea, North Korea's arch-rival.

South Korea's foreign ministry has said that discussions during the two-day visit will focus on the Korean peninsula where China is pressing to restart the stalled six-nation talks on the North's nuclear disarmament.

South Korea, supported by the US and Japan, says the North must take steps to show it is serious about scrapping its atomic arsenal before the talks can resume.

China is South Korea's biggest trade partner and relations were upgraded to a "strategic cooperative partnership" in 2008.

The US and North Korea will hold two days of talks. They had their first round of direct talks in New York in July, which ended with Washington demanding a firm commitment from Pyongyang to disarm.