The announcement comes after NATO scrambled jets to shoot down Russian drones over allied airspace for the first time since the war in Ukraine started three-and-a-half years ago.

"NATO is launching Eastern Sentry to bolster our posture even further along our eastern flank," Rutte told a joint news conference with NATO's top commander in Europe, US General Alexus Grynkewich.

"This military activity will commence in the coming days and will involve a range of assets from allies including Denmark, France, United Kingdom, Germany," Rutte said

He said the reinforcements would include "more traditional military capabilities" in addition to "elements designed to address the particular challenges associated with the use of drones".

NATO is still assessing whether Russia had intentionally violated Poland's airspace or not, he added, but repeated that either way "it is reckless. It is unacceptable."

NATO's announcement comes after allies including France and Germany said they would send more fighter jets to Poland.

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

"Eastern Sentry will be flexible and agile, delivering even more focused deterrence and defence exactly when and where needed," he added.

NATO has hailed as a success its response to the incursion that saw the latest US-made fighter jets scrambled to shoot down relatively inexpensive Russian drones.

But there have been questions over why only a handful of the drones that entered Polish airspace were apparently destroyed.

"We are always looking for ways to enhance, to learn from the smallest tactical error to how we're approaching certain problems," Grynkewich said.

"The scale of the incursion the other day was obviously larger than previous incursions that we've had. So bringing additional resources to bear on this problem will help to solve that."

He added that NATO was making efforts to make sure "we get lower cost weapons that we can use to defend ourselves, to make this a sustainable operation over time".

"When there's a fighter pilot that's in the air, or someone on the ground who's defending the alliance, I don't want them thinking about how much their weapons cost. I want them defending our citizens," he said.

Poland's Defence Minister Wladyslaw Kosiniak-Kamysz thanked NATO for its "decisive action and decisions in response to Russia's aggressive policy".

The new deployment was "not only a strategic decision" but "an expression of responsibility for the security of the entire eastern flank of the alliance," he added.