MANILA - Presidential Spokesperson Salvador Panelo on Monday said the Philippines has protested the reported presence of a large number of Chinese vessels around the Philippine-held Pag-asa Island (Thitu Island) in South China Sea.

Panelo said he was told by the military that the Philippines, through the foreign affairs department, filed the protest. He, however, failed to provide more details.

“Anything that concerns the security of the Philippines will always be a concern... I understand we have already issued a diplomatic protest, per the Western Command,” he said in a press briefing.

The Western Command of the Armed Forces of the Philippines on Friday reported the presence of Chinese vessels around Pag-asa Island, the second largest naturally occurring island in the disputed sea, noting that these were very near the Philippine island and are almost stationary.

Over 600 Chinese vessels have been circling Pag-asa Island (Thitu Island) in the West Philippine Sea since January this year, the military said.

On Feb. 10, the military recorded the highest number of Chinese vessels circling Pag-asa Island at 87. It was also on this day that the military brought construction equipment to the island for the repair of a runway ramp that is expected to be finished by July this year.

Panelo said he will also raise with Chinese Ambassador to the Philippines Zhao Jianhua the continued presence of Chinese vessels around Pag-asa Island.

• Hundreds of Chinese vessels circling Pag-asa Island: military

Panelo said he would not confront the Chinese envoy about the reported incidents yet when they meet on Monday afternoon, as he will give the latter a chance to clarify matters.

“We will ask if this is true as far as they are concerned. And number two, if it is true, what are they doing there?” Panelo said in a press briefing.

Panelo said if Zhao acknowledges the presence of a large number of its fishing vessels around Pag-asa Island, Manila will "ask them why they are doing it" and "ask them politely not to do what they are doing."

But he also downplayed the presence of the Chinese maritime militia vessels around Pag-asa Island.

“Ibig sabihin pag nagsi-circle, meron kang binabalak. Pero kung stationary ka lang, baka nanonood ka lang, nakatingin ka lang,” Panelo said.

(When you say circling, it could mean you intend to do something. But if you are stationary, you could just be watching.)

Observers say the Chinese maritime militia vessels, which do not belong to the military or coast guard, are meant to enforce Chinese claims to the disputed sea and intimidate citizens from other claimant-states.

Aside from the issue involving the Chinese maritime militia vessels, Panelo said he might also raise the reported harassment of Filipino fishermen at the rich fishing ground of Scarborough Shoal, located within the Philippines 200-nautical mile exclusive economic zone.

• Palace on reported Scarborough harassment: 'May magagawa ba tayo?'

China has refused to accept the decision of an international tribunal invalidating its expansive claim to the South China Sea, and instead has ramped up its construction activities in the artificial islands it built in the disputed sea lane.

President Rodrigo Duterte has also chosen to downplay Manila's maritime dispute with Beijing as it pursued improved economic ties with the regional power and world's second largest economy.