NATO Secretary General Jens Stoltenberg has said that NATO will guarantee that Moscow understands that a nuclear was should never be fought and cannot be won.

He said this during the online discussion "Reuters NEXT Newsmaker with Jens Stoltenberg" on Wednesday.

Asked whether Russian President Vladimir Putin was bluffing when saying that he would use all available means to defend Russia, Stoltenberg said, "This is dangerous and reckless nuclear rhetoric. It's not new as he has done it many times before. He knows very well that a nuclear war should never be fought and cannot be won, and it will have unprecedented consequences for Russia. And therefore NATO has also increased its presence, especially in the eastern part of the Alliance, also to remove any room for miscalculation or misunderstanding in Moscow."

To a question what NATO would do if Russia uses nuclear weapon in Ukraine, the Secretary General said NATO will guarantee that Moscow understands that it is impossible to win this war, adding that NATO's response will depend on the situation and what kind of weapons they can use. The most important thing is to prevent this, he emphasized.

"We are communicating very clearly that we monitor very closely what Russia does. So far we have not seen any changes in the nuclear posture, the nuclear readiness, but we monitor this very closely and we stay vigilant," Stoltenberg said.