MOSCOW (AP) — President Vladimir Putin says Russia would only use its nuclear weapons in response to an incoming missile attack.

Putin said Thursday Russia's military doctrine doesn't envisage a preventative nuclear strike. He noted that Russia would only launch a nuclear strike if its early warning systems spot missiles heading toward its territory, adding that "the aggressor should know that retaliation is inevitable."

Speaking at a policy forum, Putin that "when we see a coming strike on the territory of Russia, we will retaliate." He acknowledged it will mean a global catastrophe, but emphasized that "we can't be those who initiated it."

"We would be victims of aggression and would get to Heavens as martyrs," while those who would launch the strike would "just die and not even have time to repent."