Opposition senator Risa Hontiveros on Friday called on President Ferdinand Marcos Jr.'s immediate actions against China's "greedy" move in the West Philippine Sea.

"The President had committed not to give up even a square inch of Philippine territory, so I expect that his administration takes definitive action on China's arrogant contempt and disrespect for our sovereignty," Hontiveros said in a statement.

"Let us take action now before we get fully invaded by the greedy foreigner," she added.

She made the remarks after photos of airfields, buildings, recreational facilities, and other structures on the artificial islands built by China in the disputed waters in WPS made rounds online.

Hontiveros said it is "angering to see the continued and growing occupation of China" in the WPS, citing the country's relentless call for the superpower country to leave the disputed waters.

"We have been calling for their abandonment in our territory for years but they kept on ignoring us," she said.

She also condemned the "illegal" occupation of China in the WPS, particularly in the Spratly Islands or locally known as the Kalayaan Island Group.

"The Philippines has not fallen short in making the Chinese govenment aware of our assertion, not least by bringing the case to The Hague and securing the 2016 legal victory. Then and there, China should have halted her activities in the WPS," she said.

"China is making it hard for the Philippines and all the other claimant countries in the ASEAN to have a productive conversation and a consensual resolution of the matter," she added.

Marcos, in his first State of the Nation Address, said his administration "will not abandon even a square inch of the territory of the Republic of the Philippines to any foreign power."

The Philippines won the arbitration case it filed against China on 12 July 2016. China, however, rejected the arbitral ruling and stood by its historic rights nine-dash line claim.

China asserted that it did not participate in the said arbitration case initiated by the Aquino administration in 2013.

In April 2021, the country filed multiple diplomatic protests against China after over 200 Chinese ships were spotted in the Julian Felipe Reef.

The Juan Felipe Reef, also known as Whitsun Reef, is approximately 175 nautical miles west of Batanza, Palawan, and within the 370-kilometer Philippine Exclusive Economic Zone.