Metro Manila (CNN Philippines, April 30) — The Philippines' Department of Foreign Affairs "strongly protested" on Thursday China's declaration of two new districts in what it calls Sansha City, which covered areas in the West Philippine Sea.

The DFA in a statement stressed that the Philippines never recognized China's "self-declared" and "unlawful establishment" of Sansha City, located south of Hainan province, which it recently said now includes the Nansha and Xisha districts.

On April 18, China said Nansha District covers islands and reefs of the Nansha Islands and their adjacent waters. The Philippines calls Nansha or Spratly Islands the Kalayaan Group of Islands.

The other district covers Xisha or Paracel Islands, which is claimed by China and Vietnam, and Zhongsha islands, which includes Scarborough Shoal, claimed by the Philippines as Panatag Shoal.

"The establishment and supposed extent of jurisdiction of 'Sansha City' of which the new two districts are part, violate Philippine territorial sovereignty over the Kalayaan Island Group and Bajo de Masinloc (Scarborough Shoal), and infringes on Philippine sovereign rights over the waters and continental shelf in the West Philippine Sea," the DFA said.

It called as "illegal" the designation of Kagitingan Reef or Fiery Cross Reef as the administrative center for the Nansha district.

"Kagitingan Reef is within the Kalayaan Island Group and is thus an integral part of Philippine territory," the DFA stressed.

It added that the 2016 arbitration ruling in favor of the Philippines already "addressed China’s excessive claims and illegal actions in the South China Sea." China rejects the ruling and insists on owning almost the entire South China Sea.

"The Philippines calls on China to adhere to international law, including the UNCLOS, as well as to the Declaration on the Conduct of Parties in the South China Sea, specifically Paragraph 5 thereof, under which parties undertake to exercise self-restraint in the conduct of activities that would complicate or escalate disputes and affect peace and stability," the DFA added.

Last week, the DFA filed diplomatic protests over China's announcement of two new districts and a Chinese warship's pointing of a radar gun at BRP Conrado Yap, considered as the Philippine Navy's "most powerful" ship.

It's not clear if there has been any response from the Chinese government, but it has so far made no public statement on the issue.

While remaining silent on the issue, the Chinese Embassy in Manila on April 24 released a music video with the song "Iisang Dagat," meant to pay tribute to frontliners in the battle against the coronavirus disease in the Philippines and in China.

It drew outrage online as Filipinos took it as a Chinese propaganda to assert ownership of the West Philippine Sea – areas Manila claims and occupies in the disputed South China Sea.

The two countries remain friends, their leaders say, as they agreed to set aside the arbitral ruling to be able to engage in joint oil and gas exploration.