The Philippines said Thursday it would ask a UN tribunal to speed up its appeal to declare China's expansive claims to the South China Sea invalid.

A formal request would be filed seeking a resolution on the case within the year or early 2015, foreign department spokesman Charles Jose said.

"We are consulting our legal team to present a request to the tribunal if it can hasten its process earlier, rather than later," Jose told AFP.

China claims most of the South China Sea, including waters near the shores of its neighbours, which has led to escalating territorial disputes.

President Benigno Aquino's spokesman Herminio Coloma also confirmed Thursday that the Philippines would repair an airstrip on Thitu island, one of the disputed Spratly islands occupied by Philippine troops in the South China Sea.

"We have funds. We will finish repairs within the year," Coloma said in a statement.

Anticipating opposition from other claimants to the area, he quoted defence department spokesman Peter Paul Galvez as saying "China's reaction will always be unfavourable".

The island, called Pagasa (Hope) by the Philippines, has hosted a small town as well as an airstrip used for civilian and military flights. However in recent years the airstrip has been allowed to deteriorate.

Department of Foreign Affairs spokesman Charles Jose said repair and maintenance work would take place "for the safety of our people there".

Coloma stressed that the airstrip had been there for years and its repair did not violate the "Declaration of Conduct" signed by most of the claimants including China and the Philippines in 2002.

The non-binding declaration effectively called on all parties to refrain from building new structures in the disputed area until the claims are settled.

New land reclamation by China was a contravention of the declaration, the statement said.

In recent months, the Philippines filed protests after it monitored reclamations in a number of outcrops that are within its exclusive economic zone but occupied by China.

On one, Johnson South Reef, the Philippines said the Chinese appeared to be reclaiming land that may turned into an airstrip.

Apart from the Philippines, China also has overlapping South China Sea claims with Brunei, Malaysia and Vietnam, a well as with rival Taiwan.

Manila lodged an appeal in March with the UN tribunal to rule the claims illegal, but China has resolutely refused to participate in the proceedings.

Foreign Secretary Albert del Rosario separately said a speedier ruling was necessary "because the situation is getting worse by the day in the South China Sea".

"So we hope to be able to get the arbitration in place, that will be the goal line for all of us," he told reporters.

"Hopefully since China is not participating perhaps we can get a quicker resolution from the tribunal," said del Rosario.

Del Rosario has said he backs a US proposal for a fresh regional dialogue for a freeze on actions that could provoke tensions in the South China Sea amid fears that Beijing has increasingly become aggressive in staking its claims.

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