"I think that’s a completely wrong statement. It's independent nations that have knocked on the door and wanted membership. It's not NATO in any way moving east—it's the east wanting to join NATO and/or the European Union. And that's the sovereign right of every sovereign nation to decide," Stoltenberg said.

According to him, "the idea that this is something that is lost for Russia and gained by the European Union is the wrong concept."

"No one has been forced to become a member of the European Union or NATO; everyone who has joined the European Union and NATO has joined because of their own free democratic will," he added.