South Korea''s chief negotiator for six-party-talks on North Korea's nuclear programme said on Thursday (August 24) he and his Japanese counterpart had agreed to try to find a momentum for the next round of talks. He added they were pessimistic about a swift return to the negotiating table. "As of now, the prospect of the resumption of the talks is quite discouraging. We agreed North Korea has not shown any sign of returning to the talks," said Chun Yung-woo after having a luncheon meeting with his Japanese counterpart Kenichiro Sasae. "It is dangerous to keep this kind of situation as it is. So we agreed to try to find a good momentum for the resumption of the talks," said Sasae. Japan's top nuclear envoy Kenichiro Sasae also met South Korea's Vice Foreign Minister Yu Myung-whan in the morning at Seoul's foreign ministry to discuss North Korea's nuclear weapons issues. Sasae, director-general of the Japanese Foreign Ministry's Asia-Oceania bureau, arrived in Seoul late on Wednesday (August 23). Separately, Song Min-soon, South Korea's chief presidential secretary on national security, will visit China for two days on Thursday and meet with Foreign Minister Li Zhaoxing to discuss the North's nuclear and missile programmes, the presidential office said. Six-country talks -- among North and South Korea, Japan, the United States of America, Russia and China -- aimed at ending the North's nuclear weapons programme are in deadlock. The last round of the talks took place in November. Proliferation experts said North Korea has been working for years to develop a nuclear weapon, but no one could say for sure if the North had actually built one. North Korea declared in February 2005 that it possessed nuclear weapons but has never proven it by testing one. U.S. television network ABC news last week reported a U.S. intelligence agency had observed suspicious vehicle movements at a suspected North Korean nuclear test site. It quoted an unidentified State Department official as saying a test was a real possibility. The North defied international warnings and test-launched seven missiles on July 5, including a long-range missile which failed.