President Donald Trump said Russian President Vladimir Putin proved to be a letdown in the months he's spent negotiating the end of the war in Ukraine.

Three Russian jets carrying ballistic missiles violated Estonia's airspace on Friday, according to the country's foreign minister.

The MiG-31 jets flew together, two NATO sources independently told Fox News Digital.

The jets flew back and forth for over 12 minutes before Italian F-35s "pushed them out," according to the sources. The jets were capable of carrying high speed, air-launched ballistic missiles called Kinzhals, the sources said. It is unclear if they were.

White House officials could not immediately be reached about the incursion.

NATO WARNS RUSSIA AFTER POLAND SHOOTS DOWN 'HUGE NUMBER' OF DRONES THAT VIOLATED ITS AIRSPACE

"Russia has already violated Estonia's airspace four times this year, which in itself is unacceptable. But today's incursion, involving three fighter aircraft entering our airspace, is unprecedentedly brazen," said Foreign Minister Margus Tsahkna. "Russia's increasingly extensive testing of boundaries and growing aggressiveness must be met with a swift increase in political and economic pressure."

Estonia is considering requesting Article 4 consultations.

Article 4 of the North Atlantic Treaty allows any NATO member to request consultations with other allies when it feels its territorial integrity, political independence or security is under threat. It does not automatically trigger a military response, as Article 5 does, but it is often used as a serious diplomatic and security warning signal.

The incident comes just days after Poland accused Russia of violating its airspace with more than a dozen drones during a major bombardment of Ukraine. Warsaw reported that at least 19 drones crossed into Polish territory from Belarus and Ukraine, forcing temporary airport closures and scrambling NATO air defenses.

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Poland shot down several of the drones and labeled the breach an "act of aggression." Prime Minister Donald Tusk described it as an "unprecedented" violation, warning that the drones posed a direct threat.

Poland invoked Article 4 consultations with NATO in response.

This is a developing story. Check back for updates.

Russian jets violate Estonian airspace, foreign minister says