MANILA - President Rodrigo Duterte has said he will "carry the voice of Asean" and raise with his Chinese counterpart Xi Jinping the arms buildup on the islands China occupies in the disputed South China Sea.
This comes as a map released recently by a Washington-based think tank showed the Philippines within range of Chinese warplanes and missiles being deployed to the South China Sea.
"I am chair of Asean, and I have to carry the voice of Asean. I have to tell the truth that everybody is worried," Mr Duterte said at a news briefing on Thursday (Nov 9) on the sidelines of an Asia-Pacific Economic Cooperation (Apec) meeting in Danang, Vietnam.
He said he will tell Mr Xi when he meets him on Saturday (Nov 11) that "the whole of Asean is worried about how we should behave in the seas that are now militarised, afraid that there might be a mistake and there would be shooting."
"Those arms, they are not there for any other purpose. They are not decorations. They are there because China would need them. For what purpose? I really don't know," said Mr Duterte.
China already has Chengdu J-10 multirole fighters, YJ-62 anti-ship cruise missiles and HQ9 surface-to-air missiles stationed on Woody island in the Paracel chain of islands near Vietnam.
The Asia Maritime Transparency Initiative (Amti) said these same aircraft and missiles, once deployed to the Spratlys archipelago, will reach Palawan province in western Philippines, and even metropolitan Manila.
China claims two-thirds of the South China Sea, a vital sea lane through which US$5 trillion (S$6.6 trillion) in ship-borne trade passes every year.
The Philippines, Vietnam, Malaysia, Brunei and Taiwan have their own claims that overlap with China's.
In 2016, an international tribunal ruled in a case filed by the Philippines that China's claims have no basis in international law. China refused to accept the ruling. It has instead fortified four of the six islands it occupies in the Spratlys with airstrips, hangars and shelters.
Analysts have said China intends to establish an "air defence identification zone" over the South China Sea and punch deeper into the Pacific, nearer US military bases in Japan and Hawaii.
"Once assets are deployed to the Spratlys, it will make life much more difficult for the Philippines and everyone else who has traditionally operated in and around the Spratlys and the waters west of the Philippines," said Amti Director Greg Poling.
Relations with China sank to historic lows under former president Benigno Aquino, as Manila pursued an aggressive approach to push back against China's expansion in the South China Sea. Mr Aquino's government filed the case in The Hague challenging Beijing's claims.
Mr Duterte opted to set aside the ruling against China's claims, as he sought warmer ties with Beijing.
In turn, China has pledged billions worth of investments and backed Mr Duterte's counter-terrorism efforts and his controversial anti-crime drive.
Mr Duterte said he will tell Mr Xi that he intends to remain a friend to China "but I have to ask him questions reflecting the sentiments of Asean".
He said he has seen surveillance photos that showed "almost all the islands (China occupies) were militarised already".
"That means those are arms that are poised to fly. So, it is not wrong for me to tell China, 'Look, you already place heavy artillery there. It (makes us) wary, worried because we are also using the passage," he said.