NATO Secretary General Jens Stoltenberg warned Moscow and Minsk Sunday against activities that would destabilize the alliance's eastern flank in an interview with German newspaper Welt am Sonntag, DW reported.

The warning comes after Belarus diverted a Ryanair flight traveling from Athens to Vilnius two weeks ago in order to detain a dissident journalist, Raman Pratasevich, and his girlfriend, Sofia Sapega, who were on board.

"We are of course ready, in an emergency, to protect and defend any ally against any kind of threat coming from Minsk and Moscow," Stoltenberg said.

He noted NATO is monitoring "what is happening in Belarus very closely," adding, "We have had to learn in the past that Russia has massively violated the territorial integrity of states such as Ukraine, Georgia and Moldova."

Stoltenberg told Welt am Sonntag that Belarus will be on the agenda of the upcoming NATO summit in one week's time. He added the current partnership agreement with Belarus is also being scaled back and reevaluated.

In response to the diverting of the Ryanair flight to arrest Pratasevich and Sapega, the EU imposed sanctions and banned EU flights from flying over Belarus and has barred Belarusian carriers from entering EU airspace.

Stoltenberg reaffirmed that NATO was a "defensive" alliance with a two-pronged approach to Russia, namely deterrence and dialogue.

By contrast, Russian leader Vladimir Putin invited Belarusian President Aleksandr Lukashenko onto his yacht near Sochi, Russia, where the two met and posed for photographs after the Ryanair incident.

Putin has underscored his support for Lukashenko, who has ruled the country since 1994.