A former top US negotiator with North Korea will visit the communist nation this week, a report said Sunday, amid efforts to revitalise long-stalled nuclear disarmament talks on Pyongyang.

The North has invited Charles Pritchard, Washington's special envoy to the North under former President George W. Bush, to visit the country, South Korea's Yonhap news agency reported, citing a diplomatic source.

"We have learned that Pritchard will visit the country around November 2 or 3 at the North's invitation," Yonhap quoted the source as saying.

South Korea's foreign ministry spokesman confirmed Pritchard's trip but not its date, saying "quite a number" of academic groups from the US are scheduled to visit Pyongyang soon.

Pritchard, who also served as senior director for Asian affairs for former President Bill Clinton, now heads the Washington-based Korea Economic Institute.

The exact purpose of Pritchard's trip is not known, but he will afterwards meet with Seoul officials to discuss its outcome, the report said.

Yonhap said that other experts including John Lewis, a Stanford University professor of Chinese politics who also studies US policy towards the Korean peninsula, and Siegfried Hecker, a professor of nuclear arms science and policy at Stanford, will soon make a trip to Pyongyang at its request.

Six-party talks aimed to curb the North's nuclear ambitions have been at standstill since the last meeting in December 2008.

In April 2009 Pyongyang stormed out of the forum, involving two Koreas, China, Japan, the US and Russia. A month later it conducted its second nuclear test.

The North has recently said it is willing in principle to return to the long-stalled nuclear disarmament talks. But Seoul and the United States say it must first improve cross-border ties and show a commitment to disarmament.