NATO Secretary General Jens Stoltenberg hit back on Monday at Russian and Chinese demands for an end to the western defence alliance’s expansion amid a stand-off over Ukraine. “This is an attempt to deny sovereign nations the right to make their own choices enshrined in key international documents,” Stoltenberg said at a press conference in Brussels, responding to a joint statement released last week. The world must “not return to an age of spheres of influence where the big powers can tell others what they can or cannot do so,” Stoltenberg said. Ukraine aspires to join NATO, but is not a memb…