China is replacing its ambassadors to South Korea and Japan in anticipation of stalled six-party talks on North Korea's nuclear program resuming, Japan's Kyodo news agency reported Saturday. China has unofficially decided to appoint its ambassador to South Korea, Cheng Yonghua, as ambassador to Japan, replacing Cui Tiankai, who is expected to become a vice foreign minister and succeed Wu Dawei as chair of the six-party talks.

Citing sources in Beijing, Kyodo wrote, "The planned appointment of Cui indicates China's willingness to move forward the six-party denuclearization talks." Until he was appointed ambassador to Japan in 2007, Cui was Beijing's no. 2 representative to the six-party talks and is recognized as a top negotiator in China. The development could suggest that the resumption of the six-party talks is imminent.

Kyodo did not say who will replace Cheng as ambassador to South Korea. Experts say it will be difficult for China to find a candidate to match South Korea's decision to dispatch chief presidential secretary and former Seoul National University professor Yu Woo-ik as envoy to Beijing. Seoul apparently hopes for a diplomatic heavyweight.

Before his appointment, Cheng was ambassador to Singapore and the first director-level official to be appointed as ambassador to South Korea. Cheng graduated from Soka University in Japan and has close ties with Japanese politicians and businessmen. Experts in Japan believe Beijing is placing more importance on relations with Seoul and Tokyo.