Japan is "playing with fire" with plans to step up activity in the contested South China Sea through joint training patrols with the United States, China's Defence Ministry said on Thursday, warning it would not sit watching from the sidelines.
China claims virtually the entire South China Sea and has repeatedly denounced what it views as interference there by the United States and its ally, Japan.
Japan is strengthening its ties in the region, in particular with the Philippines and Vietnam, which contest China's claims to parts of the sea, and it aims to help build the capacity of coastal states in the busy waterway, its defense minister said this month during a visit to Washington.
