Russian President Vladimir Putin would only consider nuclear weapons in the event he feels an “existential threat” to his country or regime, according to foreign policy experts.

“They could be used, but in very, very specific situations,” former Russian foreign minister Andrei Kozyrev told Fox News Digital. “If Russia or one of those countries really threatened in their hearts – existentially, that is … if NATO troops come to Moscow, then probably they will resort to nuclear weapons.”