Earlier Friday, Estonian officials confirmed to POLITICO that three warplanes had crossed into Estonian airspace and were forced out after Italian jets were scrambled to deal with what the EU’s top diplomat, Kaja Kallas, described as an “extremely serious provocation.”

“We need to understand that Putin doesn’t want to have any kind of peace in Ukraine,” Tsahkna said. “Instead, Putin is bombing Ukraine, killing people in the middle of the day … also more actively against NATO.”

Estonia, the top diplomat confirmed, has triggered Article 4 of NATO’s treaties, which calls for urgent discussions with allies.

“Russia is testing NATO, the unity of Europe,” he said. “The Eastern flank is taking more responsibilities. We are the first line … Article 4, we call it now and we need to have a conversation about what can we do more.”

In a statement early Saturday, Moscow denied that its jets violated Estonia airspace. “On 19 September, three Russian MiG31 fighter jets made a scheduled flight from Karelia to an airfield in the Kaliningrad region,” Russia’s foreign ministry said in a statement on social media. “The aircraft did not deviate from the agreed route and did not violate Estonian airspace,” is said.

The incident is the third such breach of NATO airspace in a matter of days — with Russian drones crossing over into Poland and Romania.