Zhang Liangui, an expert on Korean Studies at Party School of Central Committee of Communist Party of China, told China Daily that Campbell's remark on Wednesday shows Washington's "pertinency" in policymaking in response to Pyongyang's recent attitudes toward the peninsula's nuclear issue.

The DPRK has stressed that its policy remains unchanged after the death of Pyongyang's former leader Kim Jong-il last December, and the takeover by his youngest son Jong-un.

However, Pyongyang recently vowed never to deal with Seoul's conservative leader Lee Myung-bak, regularly censured by Pyongyang's state media for his hardline policy.

"Given Pyongyang's recent stances toward denuclearization and its ties with Seoul, it may not give a positive response to the possible accesses proposed by Campbell to either the resumption of Six-Party Talks or the improvement of DPRK-ROK ties," Zhang said.

Meanwhile, the US special representative for the DPRK policy Glyn Davies is paying a visit to Russia from Tuesday to deepen cooperation and share perspectives on Pyongyang, according to the US Department of State.

Lim, the envoy with Seoul, is expected to visit Russia next week to meet his Russian counterpart and Deputy Foreign Minister Igor Morgulov, Yonhap News Agency said on Tuesday, adding that the schedule has not been finalized.

Recent frequent exchanges of views among the related parties in the Six-Party Talks show that the countries concerned "have decided to wrap up hesitation" after the death of Kim Jong-il , Zhang said.

The nuclear talks grouping the DPRK, the ROK, China, Japan, Russia and the US were last held in December 2008. Pyongyang walked out in April 2009.