China has stressed its firm opposition to Japan and the Philippines launching maritime delimitation negotiations regarding waters located east of China's Taiwan island, saying the move seriously infringes upon China's maritime rights and interests.

Foreign Ministry spokeswoman Mao Ning made the remarks after Japan and the Philippines issued a joint statement during Philippine President Ferdinand Marcos Jr.'s visit to Japan on Thursday announcing that they would formally begin negotiations on the delimitation of their exclusive economic zones and continental shelves.

The waters the two countries intend to delimit are located east of China's Taiwan island, Mao said on Friday. Under Chinese domestic law and international law, including the United Nations Convention on the Law of the Sea, China is entitled to an exclusive economic zone and continental shelf in the area, she said.

Japan and the Philippines have unilaterally launched so-called maritime delimitation negotiations, which seriously infringe upon China's maritime rights and interests and seriously violate international law, as well as the basic norms governing international relations, Mao said.

China has lodged solemn representations with both Japan and the Philippines, she added.

Mao stressed that the delimitation negotiations between Japan and the Philippines are completely illegal and invalid, and will have no impact on China's claims to rights in waters east of Taiwan island or on China's exercise of its lawful rights.

China urges Japan and the Philippines to immediately halt any actions that infringe upon China's maritime rights and interests, and to take concrete steps to safeguard regional peace and stability, she said.