The United States has called out China for interfering in the Philippines' maritime operations and undermining regional stability, urging Beijing to stop "its dangerous and destabilising conduct" in the South China Sea.

Chinese militia vessels operate at Whitsun Reef in South China Sea

The Philippines and China have traded accusations over a ramming incident during the weekend while Manila's vessels were on a resupply mission to Second Thomas Shoal, where its soldiers are stationed.

"Obstructing supply lines to this longstanding outpost and interfering with lawful Philippines maritime operations undermines regional stability," State Department spokesperson Matthew Miller said in a Dec. 10 statement shared by the U.S. embassy in Manila on Monday.

The United States has called on China to comply with a 2016 arbitral ruling that invalidated its sweeping claims in the South China Sea.

A commentary piece in China's official military newspaper urged the Philippines to immediately stop its violations, strictly control its provocative actions, and "refrain from shooting itself in the foot".

It added that "some hegemonic countries" have resorted to "instigating trouble, creating division and inciting confrontation" in the South China Sea, and that those countries "openly endorsed" illegal infringement and provocation by the Philippines.

"It must be pointed out that the Philippines' actions are closely connected to the instigation and abetment of external forces," the PLA Daily said, without naming any country or government.

During the weekend, the Chinese coastguard said China would continue to carry out "law-enforcement activities" in its waters.

The United States also reiterated its support for its treaty ally, the Philippines, and reaffirmed its commitment to the mutual defence pact between the two countries.

Philippines President Ferdinand Marcos Jr. separately said that the presence of Chinese coast guard vessels and maritime militia in his country's waters is illegal and that their actions against Filipinos are outright violations of international law.

The Philippines has further steeled its determination to defend and protect its nation's sovereign rights in the South China Sea amid "aggression and provocations" by China, Marcos posted on the X social media site late on Sunday.

"We remain undeterred," the president said.