MANILA - Senior Associate Justice Antonio Carpio believes the Philippines will receive a favorable ruling in the arbitration case filed against China before the Permanent Court of Arbitration.

The arbitration ruling is expected next month but Carpio could not confirm a specific date.

China claims almost the entire South China Sea, through which about $5 trillion worth of ship-borne goods passes every year. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims to the waters.

Beijing has refused to recognize the case lodged by the Philippines with the Permanent Court of Arbitration in The Hague over territorial claims in the South China Sea and says such disputes should be resolved through bilateral talks.

Manila is challenging the legality of China's claim there, in part by arguing that no land mass in the Spratly archipelago, including Itu Aba, known as Taiping Island in Chinese, can legally be considered a life-sustaining island.

That would mean it cannot hold rights to a 200 nautical mile (370 km) exclusive economic zone.

China slams PH definition of South China Sea 'reef'

Carpio is positive that the ruling will favor the Philippines because China's stand on the 9-dash lines is totally incompatible with international law.

"I don't know of any credible international law of the seas scholar other than the Chinese who say that the 9-dash lines can be upheld in the international law. It's totally incredible that a country will claim an entire sea," he said.

Carpio expressed strong confidence that the Philippines will win the arbitration, saying even the deputy foreign minister of China expects Beijing to lose.

Assuming that the Philippines wins, the ruling will be used to campaign for world support and convince China to follow international laws. Carpio said that since the ruling is authorized under the United Nation Convention on the Law of the Sea (UNCLOS), it becomes authoritative.

"Because right now, it's our word against China's. When we go to the world asking for their support we can call it."

China to reject arbitration ruling on disputed sea

Meanwhile, President-elect Rodrigo Duterte has already mentioned that he will wait for the ruling of the tribunal and will base the Philippines' response on what the ruling says. "I think when when the President-elect said that he would ride a jetski to carry the flag and plant it there, that's a figure of speech. It means geographically, he is willing to defend it." With reports by Reuters and Kyodo News