Polish authorities have recorded and tracked 19 crossings into Polish airspace by Russian drones.
Poland activated Article 4 of the NATO Treaty on Wednesday to allow for consultations with allies hours after its armed forces downed multiple Russian drones that had entered its airspace.
"The shooting down of drones threatening our security is a success for Polish and NATO forces, which simultaneously changes the political situation," Prime Minister Donald Tusk said.
"In this regard, allied consultations have taken the form of a formal request to activate Article 4 of the North Atlantic Treaty," he added. His decision was made after consultation with President Karol Nawrocki.
Article 4 of the North Atlantic Treaty provides for the possibility of joint consultations between NATO allies "whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened".
Polish armed forces downed multiple Russian drones over the country's territory on Wednesday morning, with the military now brought to its "highest state of readiness".
The first violation of the airspace was recorded at around 11:30 pm CEST on Tuesday evening, with the last one observed at 6:30 am CEST on Wednesday morning.
Local police confirmed that debris believed to be from a damaged drone was found in the village of Czosnówka in eastern Poland, close to Poland's border with Belarus.
Warsaw's Chopin Airport said it remained open but "there were no flight operations for the time being." Warsaw Modlin, Rzeszów-Jasionka and Lublin airports also suspended flights.
'Reckless behaviour'
NATO chief Mark Rutte said in the early afternoon on Wednesday that in their consultations, "allies expressed solidarity with Poland and denounced Russia's reckless behaviour".
He added that a "full assessment" of what happened is now ongoing and that the alliance "will closely monitor the situation along our eastern flank, our air defences continually at the ready".
"To Putin, my message is clear: stop the war in Ukraine, stop escalating the war, which is now basically mounting on innocent civilians and civilian infrastructure, stop violating allied airspace and know that we stand ready, that we are vigilant and that we will defend every inch of NATO territory," Rutte emphasised.
In an address to the Sejm, the country's parliament, Tusk had earlier stressed that this was the first time since the beginning of Russia's illegal full-scale invasion of Ukraine in early 2022 that its airspace was violated not "as a result of mistakes" or "small Russian provocations" but that the drones "flew directly from Belarus".
He also said that he had already been in contact with multiple leaders, including those who "see the Russian threat clearly": Finland, Denmark, Norway, Sweden, and the Baltic states. He also spoke Rutte.
NATO assets from Italy, the Netherlands and Germany were involved in shooting down the Russian drones. It is the first time NATO aircraft have engaged potential threats in allied airspace, the alliance's Supreme Headquarters Allied Powers Europe (SHAPE).
It added that it is "in close contact and coordination with Poland and other allies regarding the drones that entered Polish airspace."
"NATO responded quickly and decisively to the situation, demonstrating our capability and resolve to defend allied territory," it added.
Tusk told the Sejm that two F-35s, two F-16s, Mi-17 helicopters, Mi-24s, and a Black Hawk were diverted to the operation.
French President Emmanuel Macron said he will "soon speak" with Rutte, describing the incursion of Russian drones into Polish airspace as "simply unacceptable".
"I condemn it in the strongest terms. I call on Russia to put an end to this reckless escalation. I reiterate to the Polish people and their government our full solidarity," he wrote on X. "We will not compromise on the security of the allies."