The Philippine DFA chief Alberto del Rosario said the Philippines wants a peaceful resolution to the dispute using the UNCLOS as basis for claiming the territory.
"The Philippines is therefore prepared to validate our claims under UNCLOS, and we cordially invite China to join us in endeavoring to validate its own claims," he said in a statement on Tuesday.
Del Rosario issued the statement after Chinese Foreign Ministry spokesman Liu Weimin insisted that China has an undisputed claim over the area.
The DFA chief, however, did not directly react to the Chinese official's claim.
Instead Del Rosario said, "We look upon our valuable and long-standing friendship with China to be one that is based on mutual respect and equality."
The Philippine government last year lodged a protest before the United Nations questioning China's claim over the Spratly Islands.
The Spratlys, a group of islets in the West Philippine Sea (South China Sea) and believed to be rich in oil and gas deposits, are being claimed in whole or in part by China, Taiwan, Vietnam, Malaysia, Brunei, and the Philippines.