MANILA, Philippines: CHINA has filed a diplomatic protest – before the Philippine embassies in Beijing and Manila – over President Ferdinand Marcos Jr.'s congratulatory message to Taiwan's new leader – Dr. Lai Ching-te.

The China Ministry of Foreign Affairs Spokesman Mao Ning said that Assistant Foreign Minister Nong Rong on Tuesday morning summoned the Philippine Ambassador to China Jaime FlorCruz "to lodge serious démarche and urge the Philippines to present a responsible response to China."

"We suggest President Marcos read more to develop a proper understanding of the ins and outs of the Taiwan question and come to a right conclusion," Mao said in a briefing.

On Wednesday, the Chinese Embassy in Manila said, "President Marcos is the only head of State to congratulate Lai among 182 countries which established diplomatic relations with China."

In a statement on Wednesday, the embassy spokesman said Marcos' remarks "seriously violate the 'One China' principle, and constitute an act of gross interference in China's internal affairs."

"China strongly opposes such remarks, and has made immediate and solemn démarches to the Philippines from both Beijing and Manila," the embassy said.

"There is but one China in the world. Taiwan is an inalienable part of China's territory, and the government of the People's Republic of China is the sole legal government representing the whole of China," it said.

The one-China principle, the embassy said, is the "political premise on which China establishes and develops diplomatic relations with 182 countries including the Philippines, a universally recognized basic norm in international relations and a prevailing consensus among the international community."

The Philippines made a solemn commitment to this in a joint communique with China signed by President Ferdinand Marcos Sr. and Premier Zhou Enlai on June 9, 1975.

"Subsequent Philippine administrations have adhered to the one-China policy," the embassy said.

Following the elections in Taiwan, the embassy noted that the Philippine Department of Foreign Affairs has issued a statement reaffirming the Philippines' commitment to the One China policy.

"Relevant remarks by the Philippine leader are at odds with the One China Principle and contradict the statement of the Philippine government, sending out erroneous signals to 'Taiwan independence' separatist forces," the embassy said.

"We urge the Philippine side to earnestly abide by the one-China principle, stop the wrong words and deeds on Taiwan-related issues, prudently and properly handle the Taiwan-related issues," the embassy said.