Prime Minister Donald Tusk said his country would formally request the invocation of NATO's Article 4 in response to the violation of his country's airspace by 19 Russian drones, some of which were shot down.

NATO's Article 4 states: "The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened."

Unlike Article 5's collective defense element, NATO's Article 4 does not trigger military action, but initiates a formal alliance discussion when one member considers its territorial integrity or security is threatened.