China's refusal to allow a UN-backed tribunal to rule on a South China Sea territorial dispute indicates Beijing's claim stands on shaky legal ground, the Philippines said Wednesday.

China and the Philippines have overlapping claims to parts of the South China Sea, which is believed to hold vast gas and other natural resources, along with Vietnam, Brunei, Malaysia and Taiwan.

Philippine Foreign Secretary Albert del Rosario called in his meetings with senior officials in Beijing last week for the dispute to go before a UN tribunal, but China on Tuesday rejected the proposal.

"China's hesitation to accept the Philippine suggestion... could lead to the conclusion that China may not be able to validate their stated positions in accordance with the UN Convention on the Law of the Sea," del Rosario said in a short statement.

The Philippines wants the dispute brought before the International Tribunal for the Law of the Sea, an independent judicial body set up by the UN convention in 1982 to handle such matters.

The Philippines and Vietnam have in recent months accused China of taking increasingly aggressive actions in staking its claims in the disputed waters, including an incident where the Chinese allegedly fired on Filipino fishermen.