Expressing serious concern over China's reported reclamation activities in the West Philippine Sea, the Department of Foreign Affairs on Wednesday said it is ready to take diplomatic action once it receives a verified report on the matter.

In a statement, the DFA called the move a violation of international law and existing agreements with claimants.

"The Department takes note of the Bloomberg article on reported reclamation activities by China in unoccupied features of the Spratlys," the agency said.

"We are seriously concerned as such activities contravene the Declaration of Conduct on the South China Sea's undertaking on self-restraint and the 2016 Arbitral Award," it added.

To recall, a Hague-based arbitral tribunal favored the Philippines over the arbitration case it filed against Beijing's nine-dash line claim.

The department said it has asked relevant Philippine agencies to verify and validate the contents of the report.

The DFA said it is prepared for diplomatic action once it receives a verified report on the alleged swarming of Chinese vessels near Iroquois Reef and Sabina Shoal in the West Philippine Sea.

"What I know is DFA is awaiting official reports and will take appropriate diplomatic action once violations have been verified," DFA spokesperson Ma. Teresita Daza said in a text message late Tuesday.

A recent news report quoted Western Command chief Vice Admiral Alberto Carlos confirming that dozens of Chinese vessels have been moving much closer to Palawan since early this year.

To date, the Philippine government has filed a total of 193 notes verbales, 65 of which were lodged under the administration of President Ferdinand R. Marcos Jr.

The most recent one was issued by the DFA on 12 December, protesting the Chinese Coast Guards' seizure of debris picked up by the Philippine Navy off Pag-asa Island.

'Fake news'
The Chinese Embassy in Manila belied claims that China is constructing new infrastructure in unoccupied features in Spratlys, calling the report "fake news".

Based on the article published on Bloomberg's website, China has been expanding its reclamation in at least four unoccupied features in the Spratlys.

Quoting an unnamed Western official, Bloomberg said the unprecedented move was part of Beijing's long-running effort to strengthen its claims in the disputed waters.

The report specifically said that reclamation activities have been taking place in Eldad Reef ((Malvar Reef) in the northern Spratlys, Lankiam Cay (Panata Island), Whitsun Reef (Julian Felipe Reef) and Sandy Cay.

Sandy Cay is about two nautical miles from Pag-asa Island, where an encounter between the Chinese Coast Guards and the Philippine Navy took place sometime in November.

Since the year started, the Philippines has filed nearly 200 diplomatic protests against China, according to the DFA.

On Tuesday, China had engaged the United States in a word war, accusing it of meddling in the South China Sea disputes after it backed Manila in expressing alarm over the "escalated swarms" of Chinese vessels.

The Chinese Embassy in Manila said the statement made by US State Department spokesperson Ned Price "contains unfounded accusations against China that attempt to stir up troubles and drive a wedge between China and the Philippines" but it did not specifically comment on nor denied the reported swarming.

It said China and the Philippines had already agreed to place the maritime row "at a proper place in the bilateral relations" and manage them through consultation and dialogue.

"The US keeps meddling in the South China Sea disputes and trying to drive wedges between countries in the region, creating tensions and harming regional peace and stability. What the US has done is not to help anyone but to serve its own geopolitical interests," it said.

"We urge the US to stop using the South China Sea issue to stir up troubles, sow discord between China and the Philippines and undermine stability in the South China Sea."

China claims most of the South China Sea under its so-called nine-dash line, which also overlaps with the Philippines' exclusive economic zone.