Online Desk: The United States renewed a warning that it would defend its treaty ally if Filipino forces come under an armed attack in the disputed South China Sea after a Chinese coast guard ship allegedly hit a Philippine patrol vessel with military-grade laser that temporarily blinded some of its crew. U.S. State Department spokesperson Ned Price said China’s “dangerous operational behavior directly threatens regional peace and stability, infringes upon freedom of navigation in the South China Sea as guaranteed under international law and undermines the rules-based international order.”

“The United States stands with our Philippine allies,” Price said in a statement after the Philippines on Monday accused a Chinese coast guard ship of using laser on Feb. 6 to block the Philippine patrol vessel BRP Malapascua from approaching the Second Thomas Shoal, a submerged reef that has been occupied by Filipino forces. “An armed attack on Philippine armed forces, public vessels, or aircraft, including those of the coast guard in the South China Sea, would invoke U.S. mutual defense commitments” under a 1951 treaty, he said. The treaty obligates the allies to help defend one another in case of an external attack.

Aside from China and the Philippines, Vietnam, Malaysia, Taiwan and Brunei also have overlapping claims in the resource-rich and busy waterway, where a bulk of the world’s commerce and oil transits. Washington lays no claims to the disputed sea but has deployed forces to patrol the waters to promote freedom of navigation and overflight — moves that have angered Beijing, which has warned Washington to stop meddling in what it says is a purely Asian dispute. The contested waters have become a volatile front in the broader rivalry between the U.S. and China in Asia and beyond.

The Chinese ship also maneuvered dangerously close, about 137 meters (449 feet), to the BRP Malapascua at one point, the Philippine coast guard said, calling the Chinese action a blatant violation of Manila’s sovereign rights. Price said the Chinese coast guard’s conduct was “provocative and unsafe” and interfered with the Philippines’ “lawful operations” in and around the Second Thomas Shoal. In July, U.S. Secretary of State Antony Blinken called on China to comply with a 2016 arbitration ruling that invalidated Beijing’s vast territorial claims in the South China Sea and warned that Washington was obligated to defend treaty ally Philippines if its forces, vessels or aircraft come under attack in the disputed waters.

On Monday, Price reiterated Washington’s call for China to abide by the 2016 ruling, adding that the “legally binding decision” underscored that China “has no lawful maritime claims to the Second Thomas Shoal.” China has long rejected the ruling and continues to defy it. In Beijing, Chinese Foreign Ministry spokesperson Wang Wenbin said Monday that a Philippine coast guard vessel trespassed into Chinese waters without permission on Feb. 6. Chinese coast guard vessels responded “professionally and with restraint at the site in accordance with China’s law and international law,” he said, without elaborating nor mentioning the use of laser. “We hope the Philippines will earnestly respect China’s territorial sovereignty and maritime rights and interests in the South China Sea and avoid any actions that may lead to the expansion of the dispute and complication of the situation,” Wang said in reply to a question at a daily media briefing, adding that both sides were in talks following the incident.

China claims the South China Sea virtually in its entirety, putting it on a collision course with other claimants. Despite friendly overtures to Beijing by former Philippine President Rodrigo Duterte and his successor, Ferdinand Marcos Jr., who met Chinese leader Xi Jinping in January in Beijing, tensions have persisted, drawing in closer military alliance between the Philippines and the U.S. The Philippines has filed nearly 200 diplomatic protests against China’s aggressive actions in the disputed waters in 2022 alone. Associated Press journalist Matthew Lee in Washington, D.C., contributed to this report.