MANILA >> The head of the Philippine military said Monday he was with his forces aboard a supply boat when it was blasted with a water cannon, surrounded and shoved by Chinese coast guard ships over the weekend in the disputed South China Sea.

China, meanwhile, accused archrival the United States of encouraging the Philippines, its treaty ally, to provoke China for its own purposes, though it provided no direct evidence.

The successive days of heated confrontations underscore China’s determination to assert its claim to virtually the entire South China Sea, despite the possibility of fomenting a larger conflict affecting shipping and other maritime activities in the crucial waterway.

Gen. Romeo Brawner Jr. told The Associated Press in a telephone interview that China was escalating its aggression in the contested waters but said it would not deter Filipino forces from defending their territorial interests.

More than 100 official Chinese and other government-linked ships have swarmed the high seas around the contested Second Thomas Shoal, where a marooned Philippine navy ship that Brawner visited has stood for decades. He said their presence was much bigger than in previous months.

“It’s pure aggression,” Brawner said. “I witnessed how many times the big Chinese coast guard and militia ships cut our path. They water-cannoned us, then bumped us. It’s angering.”

“This really needs a diplomatic solution at the higher level,” he said, but added that the armed forces would continue to support front-line troops and protect fishermen.

Brawner, the U.S.-educated chief of the 150,000-member Armed Forces of the Philippines, joined navy personnel in a wooden-hulled supply boat, the Unnaiza Mae 1, which brought Christmas gifts, food and other supplies to a small contingent of Filipino marines and navy personnel stationed aboard the BRP Sierra Madre at Second Thomas Shoal.

Although now crumbling with rust and holes, the slightly listing Sierra Madre remains an actively commissioned Philippine navy ship, meaning any assault on it would be considered an act of war. It has become a fragile symbol of the territorial claims of the Philippines.

Brawner said he conveyed President Ferdinand Marcos Jr.’s Christmas greetings to the Filipino forces and shared with them a traditional rice lunch.

The United States has repeatedly warned it is 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. China has warned the U.S. not to meddle in what it says is a purely Asian dispute.

Chinese Foreign Ministry spokesperson Mao Ning reinforced that message at a daily briefing Monday, saying the maritime disputes were “issues between the two countries, and no third party has the right to intervene.”

“Recently, the U.S., in order to realize its own geopolitical interests, has encouraged, supported, and cooperated with the Philippines in its violations and provocations in the South China Sea, exaggerating differences and inciting confrontation,” Mao told reporters.

Over the weekend, Philippine officials said the Chinese coast guard and suspected militia ships targeted Philippine vessels two days in a row with water cannon blasts and rammed one of them, causing damage and endangering crew, off Second Thomas Shoal and separately in Scarborough Shoal off the northwestern Philippines.

More than a dozen countries, including the U.S., Japan, the European Union, Germany, France, Canada and Australia, expressed support for the Philippines and concern over the incidents, Department of Foreign Affairs spokesperson Teresita Daza said.

Philippine officials said the Chinese coast guard’s high-pressure water cannon blasts disabled and damaged the engines of the Philippine supply boat M/L Kalayaan, which had to be towed back to a Philippine port. One of two Philippine coast guard escort ships, the BRP Cabra, sustained damage to its mast.

The Chinese coast guard said it had “implemented controls in accordance with laws and regulations.” The statement gave no details about the measures taken but said the Philippines action “seriously infringed on China’s sovereignty.”

“The responsibility lies entirely with the Philippine side,” the Chinese coast guard said.

The U.S. State Department said the actions by China’s ship “were dangerous and unlawful” and undermined regional stability. It renewed a vow that it would defend Philippine forces if they face an armed attack.

China has rejected all international condemnation and attempts at legal intervention, including a 2016 ruling by a U.N.-backed arbitration tribunal that invalidated China’s claims, leaving them without any legal basis. China says it has a legal right to “defend its sovereignty” in keeping with its expansive claim to the South China Sea.

On Saturday, the Chinese coast guard and accompanying ships also trained water cannons at three Philippine fisheries vessels, causing damage to one, to prevent them from approaching Scarborough Shoal. Officials said that Chinese vessels used a long-range acoustic device that could impair hearing, causing “severe temporary discomfort and incapacitation to some Filipino crew.”

In other high seas clashes this year, Philippines officials said that Chinese coast guard ships used a military-grade laser that caused Filipino crew members temporary blindness and engaged in dangerous blocking and shadowing maneuvers that caused minor collisions.