The China Coast Guard conducted law enforcement patrols in waters east of Taiwan island on Monday in response to Japan and the Philippines unilaterally launching maritime delimitation talks in such waters, a spokesman said.

The operation was carried out by CCG's Daishan vessel formation in accordance with the law, the agency's spokesman Jiang Lue said in a statement.

The move was a necessary action in response to Japan and the Philippines' unilateral announcement of launching maritime delimitation talks in waters east of Taiwan island, which seriously infringed upon China's territorial sovereignty and maritime rights and interests, Jiang said.

"We urge Japan and the Philippines to immediately stop all illegal actions that infringe upon China's sovereignty and rights," Jiang said.

He noted that the China Coast Guard will continue to strengthen control over relevant waters and take concrete actions to firmly safeguard national territorial sovereignty and maritime rights and interests.