NATO Secretary-General Mark Rutte on Wednesday condemned Moscow after several of its drones were shot down in Polish airspace, warning Russian leader Vladimir Putin that the transatlantic alliance was “ready” for further incursions.

While the military alliance chief said “a full assessment of the incident” was still ongoing to determine whether the attack was intentional, “what is clear is that a violation last night is not an isolated incident.”

“Our air defenses are continually at the ready,” Rutte told reporters in Brussels, after fighter jets shot down the Russian swarm. “My message is clear: stop the war in Ukraine … stop violating allied airspace, and know that we stand ready, that we are vigilant and that we will defend every inch of NATO territory.”

This article is being updated.