The circumstances in which NATO might have to use nuclear weapons are "extremely remote", the Western defence alliance's secretary-general said on Wednesday, adding however that there would be "severe consequences" if Russia used such weapons.
"There would be severe consequences if Russia used nuclear weapons, any kind of nuclear weapon against Ukraine," Jens Stoltenberg told a news conference after a meeting of NATO defence ministers.
"We will not go into exactly how we will respond, but this will fundamentally change the nature of the conflict. It means that a very important line has been crossed," he said, referring to the war in Ukraine that followed Russia's invasion of the country.
He said the fundamental purpose of NATO's nuclear deterrent was to preserve peace and prevent coercion against its allies, and so the circumstances under which it might have to use nuclear weapons were "extremely remote".