In response, China warned that relations were at a crossroads and the Philippines should choose a prudent path forward.

Two Chinese coast guard ships hit a Philippine navy-operated supply boat with water cannons Saturday in the latest and most serious confrontation between the rival Asian claimants near the disputed Second Thomas Shoal, which is surrounded by Chinese vessels in a bid to dislodge Philippine forces from there.

The repeated high-seas confrontations since last year have sparked fears of a larger conflict that could put China and the United States on a collision course. The U.S. has warned repeatedly that it’s obligated to defend the Philippines — its oldest treaty ally in Asia — if Filipino forces, ships, or aircraft come under an armed attack, including in the South China Sea.

The United States, the European Union, Japan, Australia, and about 16 other countries have expressed support for the Philippines and the rule of law, according to the Department of Foreign Affairs in Manila.

China accused Philippine vessels of “intruding” into Chinese waters. Foreign Ministry spokesperson Lin Jian said that the actions of the Chinese coast guard were “legitimate, professional and restrained” and that China would "continue to take resolute measures to safeguard its territorial sovereignty and maritime rights and interests.”

The Chinese Embassy in Manila stated by the Chinese coast guard warned the Philippines against “playing with fire."

Philippine Foreign Undersecretary Theresa Lazaro in a phone call with her Chinese counterpart expressed “the Philippines’ strongest protest against the aggressive actions undertaken by the China coast guard and Chinese maritime militia against the rotation and resupply mission undertaken by the Philippines,” the Department of Foreign Affairs said in a statement.

Chinese Vice Foreign Minister Chen Xiaodong told Lazaro that relations between their countries are at a crossroads and that the Philippines must act prudently in deciding which path to follow, a statement from the Chinese side said.

He accused the Philippines of provoking incidents at Second Thomas Shoal and attempting to transport supplies without China’s permission to an illegally beached ship in a bid to achieve long-term occupation of the reef, the statement said.

The Philippines separately summoned a senior Chinese diplomat in Manila to convey its protest and demand that Chinese ships immediately leave the waters around Second Thomas Shoal, which lies in the Philippines’ exclusive economic zone, and for China to stop violating international law.

Philippine defense, security, and foreign affairs officials convened a meeting Monday to discuss new steps to deal with what they say is China’s unacceptable and provocative actions in the South China Sea. Their recommendations would be submitted to President Ferdinand Marcos Jr. and were not immediately released to the public.

Second Thomas Shoal has been occupied by a small contingent of the Philippine navy and marines on a marooned warship since 1999 but has been surrounded by the Chinese coast guard and other vessels in an increasingly tense standoff. It’s the second time the Philippine supply boat has been damaged by water cannon in March.

The U.S. lays no claims to the busy seaway, a key global trade route, but has deployed Navy ships and fighter jets in what it calls freedom of navigation operations that have challenged China's claims to virtually the entire South China Sea. Beijing says the strengthening of U.S. alliances in Asia, including with the Philippines, is aimed at containing China and threatens regional stability.

Aside from China and the Philippines, Vietnam, Malaysia, Taiwan, and Brunei also have overlapping claims in the resource-rich and busy waterway. Beijing has refused to recognize a 2016 international arbitration ruling that invalidated its expansive claims on historical grounds.