ISTANBUL

China chided the US on Monday over the United Nations Convention on the Law of the Sea (UNCLOS) in a broadside over its support for the Philippines following the latest in a series of flare-ups between the two Asian countries.

“BTW, when will the US ratify UNCLOS?” Vice-Foreign Minister Hua Chunying retorted on X after US State Department spokesman Matthew Miller accused Beijing of “provocations” in the disputed South China Sea after the Philippines claimed that China’s coastguard used a water cannon on Saturday against a Philippine civilian boat supplying troops at the Second Thomas Shoal.

Miller said this “resulted in injuries to Filipino crew members, undermined regional stability and showed clear disregard for international law.”

However, Hua countered that if Manila “had repeatedly reneged on its commitments made to the US, it should have expected a much stronger response from the US.”

If the US “truly wants to see peace and stability in the South China Sea, it should stop condoning and abetting the Philippines’ provocation of attempting to build a permanent outpost on the uninhabited reef, in violation of its DOC commitment,” she said, referring to negotiations between China and the ASEAN nations over maritime claims in the disputed waters.

China claims that the Philippines had promised to relocate its rusting warship from disputed waters, while Manila denies this.

Beijing has regularly tried to block Manila’s resupply operations to the BRP Sierra Madre, a grounded navy ship that serves as an outpost at Second Thomas Shoal in the Spratly Islands.

Hua’s statement came after Manila summoned the Chinese envoy on Monday to issue a "strong protest" over "aggressive actions" by the Chinese Coast Guard against its rotation and resupply mission in the South China Sea on Saturday.

Beijing and Manila have a long history of maritime territorial disputes in the South China Sea, including frequent confrontations between their vessels near disputed reefs in recent months.

In the latest incident, Manila alleged that the Chinese Coast Guard blocked its supply vessel and damaged it with a water cannon, injuring three crew members near the Second Thomas Shoal during a regular mission.

Beijing and Manila have conflicting claims over the Second Thomas Shoal, also known as Ayungin Shoal, Bai Co May and Ren'ai Jiao, which is a submerged reef in the Spratly Islands in the South China Sea.

"The Philippines demands that Chinese vessels leave the vicinity of Ayungin Shoal and the Philippine exclusive economic zone immediately,” said a statement by the Philippine foreign affairs department.

It urged China to take the "correct track of abiding by international law and respecting the legitimate rights of other states like the Philippines and to cease and desist from its continued violation of international law, including the 1982 UNCLOS and the 2016 Arbitral Award."

Beijing demanded that Manila “immediately stop infringing and provoking.”

“If they continue to act recklessly, China will continue to take resolute measures to safeguard its territorial sovereignty and maritime rights and interests,” Foreign Ministry spokesman Lin Jian told reporters in the Chinese capital.

China’s Coast Guard has defended its actions, describing them as "lawful regulation, interception and expulsion" of a foreign vessel that "tried to forcefully intrude" into Chinese waters.

Amid the escalating situation, Chinese Deputy Foreign Minister Chen Xiaodong spoke to his Filipino counterpart Maria-Theresa Lazaro on Monday.

Chen made “stern representations on issues including the Philippines' transportation of supplies to the illegally "beached" military ship on Ren'ai Reef,” the ministry said in a statement.

“China-Philippines relations are currently at a crossroads, and the Philippines must act prudently,” Chen said in what was perceived as a tense conversation.

*Aamir Latif contributed to this story from Pakistan.