Western powers are “not returning to the Cold War” despite renewed military threats from Russia, a top NATO diplomat emphasized one day after Russian President Vladimir Putin claimed to have developed an “invincible” nuclear weapons system.

“We are trying to be judicious about deterring and defending at this moment in history, but not returning to the Cold War,” NATO Deputy Secretary General Rose Gottemoeller said during a town hall in Greece. “I think it’s very important to focus on the differences with the Cold War.”