China Coast Guard vessel Sandu patrols in South China Sea. (Photo/Xinhua)

Beijing - The China Coast Guard (CCG) said it conducted a law-enforcement patrol in waters east of China's Taiwan Island Monday in response to Japan and the Philippines' unilateral announcement of maritime delimitation talks in the area.

The move by Japan and the Philippines seriously infringes upon China's territorial sovereignty and maritime rights and interests, and the patrol was a necessary action taken against it, said Jiang Lue, a spokesperson for the CCG.

"We urge Japan and the Philippines to immediately cease all illegal actions that undermine China's sovereignty, rights and interests," Jiang said.

The CCG will continue to strengthen control over relevant waters and take measures to safeguard China's territorial sovereignty and maritime rights and interests, the spokesperson added.