The Philippines has sought recognition from the United Nations for its claim to an extended continental shelf off the island that is closest to a hotly disputed region of the South China Sea.

China claims almost the entire waterway through which trillions of dollars in ship-borne trade passes annually, and huge unexploited oil and gas deposits are believed to lie under its seabed.

The sea is also important as a source of fish for growing populations.

In the submission filed Saturday, Manila claimed it was entitled to "establish the outer limits of its continental shelf" up to 350 nautical miles (648 kilometres) off the western island of Palawan, the maximum allowed under the UN Convention on the Law of the Sea (UNCLOS).  

"The seabed and the subsoil extending from our archipelago up the maximum extent allowed by UNCLOS hold significant potential resources that will benefit our nation and our people for generations to come," said Marshall Louis Alferez from the Department of Foreign Affairs.

"Today we secure our future by making a manifestation of our exclusive right to explore and exploit natural resources in our ECS entitlement," said Alferez, who is the assistant secretary for maritime and ocean affairs.

Manila and Beijing have a long history of maritime territorial disputes in the South China Sea, but tensions have worsened in the past 18 months. 

China has brushed aside rival claims to the sea and ignored an international ruling that its expansive claims over the waters are without legal basis. 

Confrontations between Chinese and Philippine vessels near disputed reefs have raised fears of a wider conflict over the sea that could involve the United States and other allies.

China's embassy in Manila did not immediately respond to requests for comment. 

Manila said its submission to the UN followed more than 15 years of scientific research of the West Philippine Sea.

The West Philippine Sea includes waters of the South China Sea that are part of the Philippines' 200-nautical-mile exclusive economic zone.  

In 2012 the United Nations recognized the Philippines' exclusive economic rights to Benham Rise, off its east coast, as part of its continental shelf.