From Reuters, via Boston.com (link):
China is unlikely to take part in an Asian security drill scheduled to begin off Shanghai on Saturday, following a misunderstanding over the purpose of the exercise, the Japan Coast Guard said.
China, the United States, South Korea, Canada and Russia are all scheduled to take part in the drill. The event would have been the first time China had participated in such a joint exercise.”We are still hoping that the Chinese will take part, but the prospects are not good,” said one Japan Coast Guard official.