China has urged a UN commission not to review a submission from Vietnam and a joint submission from Malaysia and Vietnam that question the location of the outer limits of the continental shelf.
Vietnam submitted information to the Commission on the Limits of the Continental Shelf (CLCS) on Thursday and presented the joint submission with Malaysia to the UN on Wednesday.
The location of the edge of the continental shelf has a bearing on the extent of national waters.
"China has indisputable sovereignty over the islands in the South China Sea and the adjacent waters, including Xisha and Nansha Islands. China enjoys sovereign rights and jurisdiction over the relevant waters as well as the seabed and subsoil thereof," said Foreign Ministry spokesman Ma Zhaoxu on Friday.
"Vietnam's submission has seriously infringed China's sovereignty, sovereign rights and jurisdiction. It's illegal and invalid," Ma said.
Ma said the Chinese Permanent Mission to the United Nations presented a note to UN Secretary-General Ban Ki-moon on Thursday, urging the CLCS not to review the submissions on the outer limits of the continental shelf beyond 200 nautical miles.
The joint submission infringed upon China's sovereignty, sovereign rights and jurisdiction in the South China Sea, the Chinese mission said.
A note from the mission posted on the UN website states that "in accordance with the United Nations Convention on the Law of the Sea and the Rules of Procedure of CLCS, the Chinese government seriously requests that the CLCS not consider the joint submission".
The Chinese government has informed Malaysia and Vietnam of the position, according to the note.
The joint submission came about one week before the May 13 deadline set by the UN for countries to submit claims over extended continental shelves. According to the CLCS Rules of Procedure, "in cases where a land or maritime dispute exists, the commission shall not consider and qualify a submission made by any of the states concerned in the dispute".
With the opposition from China, the CLCS will not consider the joint submission in line with the rules of procedure, a spokesman told Xinhua.
Analysts said Malaysia and Vietnam intend to define their position and rights in the South China Sea through the joint submission. "By submitting information to the commission, the two countries also intend to internationalize the South China Sea issue, " said Wang Hanling, an expert on marine law with the Chinese Academy of Social Sciences, adding that "negotiation is the best way to solve disputes in the South China Sea, and cooperation benefits all countries in the area."
Xinhua contributed to the story