US Defense Secretary Pete Hegseth reaffirmed Washington’s “ironclad” commitment to a mutual defense treaty with the Philippines during a call with his counterpart in Manila in the face of geopolitical tensions in South China Sea.

The joint patrol on Tuesday over the Scarborough Shoal was the first by the longtime treaty allies since President Donald Trump took office again.

The Chinese military carried out combat readiness patrols in waters and airspace surrounding a hotly disputed Sea shoal on Friday, the latest in a series of exercises to reinforce its control of the area.

The Philippine coast guard says Chinese coast guard ships and a Chinese navy helicopter harassed a group of Philippine fisheries vessels conducting a scientific survey in a hotly disputed area of the South China Sea,

China has conducted military patrols in the South China Sea while the Philippines was holding joint naval drills with the U.S., Japan and Australia, saying Manila is undermining Beijing's claims in the region.

It followed Tuesday’s PLA air patrol over the contested Scarborough Shoal – known as Huangyan Island in China. The Chinese military activities came after the Philippines and the United States held a joint patrol over the South China Sea on Tuesday,