After multiple Russian drones violated NATO airspace, Europe faces questions over the alliance’s long-term ability to deal with this growing threat.

"If it had all happened at once, maybe you could call it an accident. But six hours of drones? That’s a test – a way to see what the West would do. And we have to respond like it’s a test," Kellogg said.

Responding to President Trump, Poland's leader said, "we would also wish that the drone attack on Poland was a mistake. But it wasn't."

In the week since NATO fighter jets scrambled to shoot down multiple dozens of Russian drones that had crossed into alliance airspace in Poland, US and Western intelligence officials have been unable to determine whether the incursion was accidental or an intentional effort by Russia to probe western air defenses and gauge NATO’s response.

A swarm of Russian drones flew last week into Poland in what officials there regarded as a deliberate provocation.