If anyone is complicating issues in the West Philippines Sea, it is China, who should stop its aggression.

Senators made the assertion Wednesday, April 28, after China demanded the Philippines to "respect" its sovereignty, and stop maritime exercises and activities that are "complicating the situation and escalating disputes".

"It is China who is building military outpost in the West Philippine Sea, destabilizing the region. And expanding their presence using militia boats," Senate President Pro Tempore Ralph Recto said in a text message to reporters.

"It is China who should refrain from escalating tensions and leave the West Philippine Sea," he pointed out.

Recto urged the Philippine government to work with its allies to contain China's growing military presence and encroachement of the Philippines' exclusive economic zone (EEZ).

The government, he added, "should do more" to protect Filipino fishermen in the area.

Senate President Vicente Sotto III rather gave China a challenge.

"We will, if they stop too," he told reporters when sought for comment on the Chinese foreign ministry's statements.

Senate Minority Leader Franklin Drilon, for his part, said China's demand showed its "total disregard" of the 2016 arbitral ruling that favored the Philippines and invalidated its sweeping, nine-dash-line claim over the South China Sea.

For administration lawmaker Sen. Francis Tolentino, the demand was "not just offensive but violates that general principle of international law that a State's territorial integrity is inviolable!"

Opposition Sen. Francis Pangilinan also told China that it is isolated from the rest international community on the issue, and thus, "should end its blatant and shameless disregard of international law."

Senator Joel Villanueva pointed out that unlike hundreds of reported Chinese militia vessels swarmed in the area, the Phiilippines' intention to patrol the WPS "is a peaceful exercise of our rights."

"It is to check on our fishing grounds. It is not an advance party of a reclamation expedition. Our ships are going there in peace," he said, alluding to China's activities in the Philippines' EEZ.

Sen. Risa Hontiveros earlier Wednesday slammed China for issuing demands against the Philippines, saying: "Beijng has been the one disrespecting the Philippines' sovereignty, not the other way around."

China's statements came after the Philippine Coast Guard started conducting drills in the WPS as part of the efforts to secure the country's maritime jurisdiction.

Last week, President Duterte conceded that "nothing will happen" if the Philippines would counter the patrols of Chinese military vessels in the WPS, "because we are not in possession of the area".

Duterte also said the issues in the WPS "remain a question forever, until such time that, you know, we can take it back".

The President said he will also "tolerate" China's fishing within the Philippines' EEZ.