NATO Secretary-General Jens Stoltenberg (Photo: AFP/VNA)

According to Stoltenberg, NATO regrets about Russia's decision but its policy remains consistent and that it is open to dialogue, including through the Russia-NATO Council, because dialogue is critical to easing mounting tensions.

A diplomatic source said that such dialogue will rely on a hotline between Russia’s chief of general staff, Valery Gerasimov, and Tod Wolters, NATO’s Supreme Allied Commander Europe, as well as Stoltenberg’s meetings with Foreign Minister Sergei Lavrov.