MANILA - The Philippines must join freedom of navigation patrols to assert its rights in the West Philippine Sea and bring China again to an arbitral court over its recent aggressions, retired Supreme Court Associate Justice Antonio Carpio said Sunday.

Chinese vessels who chased a Filipino boat carrying fishermen and an ABS-CBN News crew violated international law since the chase happened inside the Philippines' exclusive economic zone (EEZ), according to Carpio.

"Violation pa rin 'yan kasi EEZ natin 'yan, there’s freedom of navigation. Kahit sino d'yan pwede magsail, hindi pwedeng hintuin, hindi puwedeng i-harass sa EEZ," he told ABS-CBN's Teleradyo.

(It's still a violation because that's our EEZ, there’s freedom of navigation. Anyone can sail, they should not be stopped or harassed in our EEZ.)

"'Yung mga freedom of navigation operations na 'yan, that is the strongest enforcement of arbitral ruling."

(Freedom of navigation operations are the strongest enforcement of arbitral ruling.)

Manila had an agreement to join the freedom of navigation patrols prior to President Rodrigo Duterte assuming office but he did not implement it due to fear of angering China, Carpio said.

"Dapat suportahan natin ito dahil every time dumadaan ang US, UK, France warships d'yan, they are asserting the ruling. Dapat sumama tayo sa kanila para makita ng Tsina na they are not in possession of the West Philippine Sea," he said.

(We should support this because every time US, UK, France warship sail though it, they are asserting the ruling. We should join them so China can see they are not in possession of the West Philippine Sea.)

The Philippines can also bring China to the Permanent Court of Arbitration in The Hague, Carpio added.

"That’s part of the legal warfare, dapat kukuha tayo ng mga ruling na ipapakita sa mundo na ang Tsina ay hindi sumusunod ng international law," he said.

(We should get rulings that will show the world that China does not follow international law.)

Manila is also urged to form a "coalition" with non-government organizations with allies and fellow claimants in the disputed South China Sea, Carpio said.

"Dapat magtayo tayo ng (We should build) nations against the 9-dash line. We will invite also people from US, Japan, Australia, that the people of the world are against the 9-dash line against China. That will give a very strong moral force against China," he said.

Malacañang, which has pursued friendlier ties with China in exchange for investments and infrastructure funding, was mum on the issue and deferred to the foreign affairs and defense department.

• Palace mum on China ships' chase of Filipino vessel in PH waters

China has been ramping up militarization and island-building activities in the resource-rich waterway, ignoring a 2016 arbitral ruling that invalidated its expansive 9-dash line claim.

Watch more in iWantv or TFC.tv