It is "not too late" for Manila to raise a United Nations-backed arbitration ruling that invalidated Beijing's sweeping claims to the South China Sea, the head of a US-based think tank said Thursday, following reports of increased Chinese activity in the area.

The UN Convention on the Law of the Sea in 2016 junked Beijing's "historic rights" to nearly 90 percent of the waterway. China has refused to recognize the ruling, which President Rodrigo Duterte refused to flaunt as he sought investments and loans from Beijing.

But recently, Philippine Foreign Affairs Secretary Teodoro Locsin insisted that the territory is "ours" following reports of Beijing's pillaging of clams there and the presence of hundreds of Chinese vessels.

International attention on the sea dispute has waned since 2016 but it may still be stoked if Manila raises its arbitration win against Beijing, said Asia Maritime Transparency Initiative Director Gregory Poling.

"It is hard, maybe impossible, to ever get that level of international attention back but it's not too late to try and it is the last best option that the Philippines has," he told ANC.

"Ultimately, the only way to right these wrongs is to convince Beijing to change its behavior and that will only happen if China sees that its action in the South China Sea are undermining its larger goal of being an international leader. Nobody wants to be led by a country that bullies its neighbors and steals their resources and destroys the marine environment," he said.

The US should also rally international support for the Philippines, its ally, as as well consider imposing economic sanctions against China, said Poling.

"China is not immune to international pressure. Beijing does care about its international reputation. If it didn't, it wouldn't make the effort to lie about these things, it tries to hide them for a reason," he said.

China has denied that the vessels circling the Philippine-occupied Pag-asa Island are part of a militia.

The world's number 2 economy is willing to investigate the poaching of giant clams by Chinese fishermen at Scarborough Shoal, a Philippine envoy said earlier this week.

DZMM, 25 April 2019