The commander of the US Navy’s largest forward-deployed fleet has reportedly responded to a recent confrontation between Chinese and Philippine ships in the South China Sea by pledging to push back against the alleged aggression of Beijing’s forces in the region.

Vice Admiral Karl Thomas, commander of the US Seventh Fleet, on Sunday assured the Philippines of Washington’s backing in countering China’s “aggressive behavior,” Reuters reported. “My forces are out here for a reason,” he said, citing the “shared challenges” faced by the US and its Philippine ally.

Thomas made his comments about three weeks after an incident in which the Chinese Coast Guard deployed water cannon against Philippine vessels that were trying to resupply a warship that Manila had intentionally grounded on a contested South China Sea shoal in 1999. The resupply mission was finally completed on Tuesday, delivering food and other goods to troops stationed on the World War II-era ‘Sierra Madre’ transport ship.

“You have to challenge people, I would say, operating in a grey zone,” Thomas told Reuters. “When they’re taking a little bit more and more and pushing you, you’ve got to push back. You have to sail and operate.” He added, “There’s really no better example of aggressive behavior than the activity on 5 August on the shoal.”

Thomas held talks with Vice Admiral Alberto Carlos, who heads the Philippine Western Command overseeing Manila’s South China Sea interests. “We certainly shared challenges,” the US commander said. “So, I wanted to better understand how he views the operations that he’s responsible for, and I want to make sure that he understood what I had available.”