The Philippines filed a claim with the U.N. on Saturday to an extended continental shelf (ECS) in the South China Sea, a waterway where it has had increasingly confrontational maritime disputes with China.
"Today we secure our future by making a manifestation of our exclusive right to explore and exploit natural resources in our ECS entitlement," Marshall Louis Alferez, foreign ministry assistant secretary for maritime and ocean affairs, said in a statement.
China claims almost the entire South China Sea, including parts claimed by the Philippines, Brunei, Malaysia, Taiwan and Vietnam. Portions of the strategic waterway, where $3 trillion worth of trade passes annually, are believed to be rich in oil and natural gas deposits, as well as fish stocks.
The Permanent Court of Arbitration in 2016 found China's sweeping claims have no legal basis, a ruling Beijing rejects.
China's embassy in Manila did not immediately respond to a request for comment on Saturday's U.N. filing.
In its confrontations with Philippine government and fishing vessels, China's coastguard has stepped up the use of water cannon,collision and ramming tactics and, according to Manila, use of a military-grade laser. An armada of Chinese fishing boats is considered by the Philippines and its allies to be a sea militia.
The Philippines sought to register its entitlement to an extended continental shelf in the West Palawan Region facing the South China Sea.
The submission, cleared by President Ferdinand Marcos Jr, follows a comprehensive technical and scientific study of continental shelf in the West Philippine Sea, the foreign ministry said, referring to a part of South China Sea within its 200-nautical-mile exclusive economic zone.
The Philippines said it was using an entitlement under the U.N. Convention on the Law of the Sea to establish the outer limits of its continental shelf, comprising the seabed and subsoil of the submarine areas up to 350 nautical miles.
The U.N. in 2012 confirmed Benham Rise, which is off the Philippines' east coast and not under dispute with China, as part of the Philippines' extended continental shelf.
(Reuters - Reporting by Neil Jerome Morales; Editing by William Mallard)