The “Eastern Sentry” operation will commence in the coming days and will involve assets from Denmark, France, the United Kingdom, Germany, and others, Rutte said.

“Eastern Sentry will add flexibility and strength to our posture and make clear that, as a defensive alliance, we are always ready to defend,” he added.

Rutte said that Russia’s “dangerous and unacceptable” drone incursion on Wednesday was “not an isolated incident.”

“Russia’s recklessness in the air, along our eastern flank, is increasing in frequency,” Rutte said.

NATO’s Supreme Allied Commander Europe, US General Alexus Grynkewich, said the operation, which will be “flexible and agile,” will include enhanced capabilities, integrated air and ground-based defences, and increased information-sharing among NATO partners.

“Although the immediacy of our focus is on Poland, this situation transcends the border of one nation. What affects one ally affects us all,” Grynkewich said.

“Poland and citizens from across the Alliance should be assured by our rapid response earlier this week and our significant announcement here today,” he said.

“NATO will continue to defend every inch of its territory.”

Drone incursion ‘wasn’t’ a mistake

Polish Prime Minister Donald Tusk on Friday called the Russian drone incursion into his country an “attack” and said it wasn’t a mistake, just hours after US President Donald Trump suggested the airspace violation could have been accidental.

Poland has information indicating that Russia launched as many as 21 drones at the country on Wednesday, but not all were found, the head of Poland’s presidential International Policy Office, Marcin Przydacz, told local media.

It’s possible that some drones went back and forth crossing the airspace, Przydacz said in an interview with Radio ZET on Friday.

Polish officials previously said that there were 19 intrusions of the country’s airspace, and that a large proportion of the drones entered from Belarus.

A total of 16 drones were found throughout the country, Poland’s interior minister said on Wednesday.

The locations where the debris was found span an area of hundreds of square miles.

It comes after Trump told reporters at the White House on Thursday that it “could have been a mistake, but regardless, I’m not happy about anything having to do with that whole situation, but hopefully it’s going to come to an end.”

Rutte said that NATO’s assessment of Wednesday’s incursion is ongoing.

“Whether or not Russia’s actions were deliberate, Russia violated NATO airspace. Therefore, we must, as NATO, make clear our resolve and our ability to defend our territory,” he said.

“And that is exactly what Eastern Sentry is designed to do.”