"We see drones violating our airspace. Whether it was a deliberate act or not, it is unacceptable. Allies have expressed their full solidarity with Poland. It is essential to resist aggression and defend every member of the Alliance," the NATO chief said, adding:"Defending the eastern flank is our primary task."

"That is why we are launching the Eastern Sentry initiative to further strengthen our eastern flank," Rutte said at a joint press conference with US General Alex Grynkewich, Supreme Allied Commander Europe.

"This military activity will be launched in the coming days and will involve various resources from allies, including Denmark, France, the United Kingdom and Germany," Rutte said.

"Integrated and multi-layered air defense, both air and ground, will be very important in the future. This was a key issue in the Baltic States, from which I recently returned."

My conversations with the leaders of Estonia, Lithuania, and Latvia focused on NATO's response to the reckless and dangerous act that occurred in Poland earlier this week.

I am extremely proud of our response. It was decisive and effective. It demonstrates the capacity and professionalism of 32 allies working together.

As the Secretary General has just said, this resolve will continue in Operation Eastern Sentry. While our focus is currently on Poland, this situation transcends the borders of one country. What affects one member of the alliance affects us all.

This is an issue that affects the entire Alliance, and we will treat it as such. Eastern Sentry will be flexible and fast, providing even more focused deterrence and defense when and where it is needed.

"It will include additional enhanced capabilities. It will integrate air and ground defense systems. It will increase information exchange between nations. Most importantly, it will further strengthen our positions to protect and defend the Alliance," added A. Grynkewich.