China has lodged serious protests with the Philippines following recent remarks by Philippine President Ferdinand Marcos Jr, who said his country could not "stay out" of a potential conflict over the Taiwan region.

"How to settle the Taiwan question is a matter for the Chinese ourselves, which brooks no interference," a Foreign Ministry spokesperson said in a statement on Friday.

The statement reiterated that: "There is but one China in the world. Taiwan is an inalienable part of China. The Taiwan question is China's internal affair which is at the very core of China's core interests." 

The spokesperson noted that the Philippine government had previously made "serious commitments" to adhere to the one-China policy, recognizing Taiwan as part of China, and acknowledging that the matter should be resolved by the Chinese people.

"These words are written in black and white, but the Philippines is now going back on its words in disregard of the grave consequences," the spokesperson said, accusing Manila of making "wrong and provocative" statements and actions, and "hollowing out" the one-China principle.

Speaking to India's Firstpost during an official visit to the country, Marcos said that if an "all-out war" broke out across the Taiwan Strait, the Philippines would "be joined into it", citing its geographic proximity and the presence of many Filipinos in Taiwan.

The ministry spokesperson warned that citing "geographic proximity" or the number of Filipinos in Taiwan as justifications for involvement "not only contravene international law and the ASEAN Charter, but also harm regional peace and stability and the fundamental interests of its own people."

"We urge the Philippines to earnestly abide by the one-China principle and the spirit of the China-Philippines Joint Communique on the establishment of diplomatic relations, and refrain from playing with fire on issues bearing on China's core interests," the spokesperson said.