The pace of Asian nuclear diplomacy accelerated Wednesday, a day after what were described as "positive" talks in Geneva between U.S. and North Korean negotiators.Chinese Vice Premier Li Keqiang met in Seoul with South Korean President Lee Myung-bak after completing talks in Pyongyang with North Korean leader Kim Jong Il. And South Korea's top nuclear envoy flew to Russia to discuss the latest progress with his Russian counterpart.U.S. Defense Secretary Leon Panetta, who arrived Wednesday in Seoul for regular defense talks, is also likely to discuss the latest round of efforts to re-start six-nation negotiations on North Korea's nuclear programs.