The Philippines says China's refusal to submit its claims to disputed areas of the South China Sea to an international tribunal demonstrates the weakness of its case.

Foreign Minister Albert del Rosario issued a statement Wednesday saying China's decision could lead to doubts about the validity of its claims.

Del Rosario proposed during a visit to Beijing this week that the countries submit their competing claims to waters near the Spratly Islands to the United Nations-backed International Tribunal on the Law of the Sea.

But at a press conference in Beijing Tuesday, foreign ministry spokesman Hong Lei said China continues to believe the dispute should be settled “through direct talks between parties concerned.”

The Philippines has complained of repeated incursions by Chinese military vessels into waters west of the Philippines island of Palawan.

The Philippines claims the waters under a provision of the Law of the Sea permitting countries to declare an exclusive economic zone extending 370 kilometers from their shores. But China claims virtually the entire South China Sea based in part on a centuries-old map.

Vietnam, Malaysia and Brunei also claim exclusive economic zones in the sea, while Taiwan claims the whole sea on the same basis as China.

The disputes have become increasingly tense in recent months as countries step up exploration for oil and gas beneath the seabed.