MELBOURNE — President Ferdinand Marcos Jr. on Wednesday expressed concern and frustration over the reported presence of Chinese research vessels at the Philippine Rise, calling it an “unnecessary escalation” of tensions in the West Philippine Sea.

“Once again, this is a clear intrusion into our maritime territory, and it is, as usual, of great concern. And I see this as absolutely unnecessary,” Marcos said in a video message before flying back to Manila.

He said the situation was unnecessary, suggesting a collaborative approach could have been taken.

“If it is truly a research vessel, then we could have come to a very simple agreement that the vessel will ply the waters and do the research that they need to do,” Marcos said.

The President, however, voiced suspicion about the vessels’ true purpose, hinting at potential ulterior motives.

“There is a suspicion that they are not only research vessels,” he said, “so, again, this is a bit of an escalation of the tension that is present in the West Philippines Sea.”

Marcos made the statement after reports surfaced earlier this week of two Chinese research vessels spotted “loitering” in the northeastern part of the Philippine Rise.

The Philippine Coast Guard said earlier this week the BRP Gabriela Silang has been on a two-week mission in Batanes and the Philippine Rise since 4 March.

Formerly known as Benham Rise, Philippine Rise is an underwater plateau along the country’s northeastern seaboard. It is believed to be rich in oil, gas, and marine resources.

It was declared part of the Philippine continental shelf by the United Nations in 2012, granting the Philippines exclusive rights to its resources. However, China has contested this claim, adding to the ongoing tensions in the region.

Ray Powell, a former US Air Force official and ex-defense attaché, raised concerns earlier this month about the appearance of two Chinese research vessels in the area.

Powell identified the vessels as the Haiyang Dizhi Liuhao and the Haiyang Dizhi Shihao, noting their transit between Basco, Batanes, and neighboring islands close to the main Luzon island.

In September of last year, reports surfaced of at least three Chinese survey ships operating near the Philippine Rise in the eastern part of the Philippine Sea.