South Korea's top nuclear envoy left for Japan Thursday for discussions on efforts to revive the stalled six-nation talks on North Korea''s nuclear weapons programs, officials said Thursday. During his three-day visit, Lim Sung-nam will meet with his Japanese counterpart Shinsuke Sugiyama and other senior officials, the foreign ministry said. Speaking to Yonhap News Agency before departing for Tokyo, Lim said he "will share views on recent situations with the Japanese side and discuss cooperative measures to resolve North Korea''s nuclear issue." The six-party talks, involving the two Koreas, the United States, China, Russia and Japan, have been dormant since April 2009 when Pyongyang left the negotiating table then conducted its second nuclear test a month later, according to South Korea''s News Agency (Yonhap). Since late July, nuclear envoys from Seoul and Pyongyang have held two rounds of meetings to discuss terms for resuming the multilateral forum, but no tangible progress has been reported. South Korea and the U.S. have insisted that the North must demonstrate its sincerity to the talks with actions, including a monitored suspension of all nuclear activities, before the six-party talks can take place. North Korea, however, is pushing to resume the forum without any conditions attached. Meanwhile, the Chinese ambassador in Seoul on Thursday called for an early resumption of the six-party talks, reiterating Beijing''s stance. Zhang Xinsen, Chinese ambassador to South Korea, told a security forum in Seoul that Beijing welcomed the two rounds of inter-Korean nuclear talks. "By continuing such dialogues, (China) hopes to swiftly resume the six-party talks and achieve permanent peace, stability and denuclearization on the Korean Peninsula," Zhang said.