Biden warns Putin to not use nuclear weapons in Ukraine, won't say what consequences would be

U.S. President Joe Biden warned Russian President Vladimir Putin against using nuclear weapons in Ukraine during an interview set to air Sunday, but he would not say what the consequences would be if the Kremlin were to detonate such weapons of mass destruction. 

When asked on "60 Minutes" about what he would say if Putin was considering using chemical or tactical nuclear weapons, Biden responded: "Don't. Don't. Don't. It would change the face of war unlike anything since World War II."

CBS reporter Scott Pelley followed up by asking what the U.S. response would be if Putin uses nuclear weapons.

"You think I would tell you if I knew exactly what it would be? Of course, I'm not gonna tell you. It'll be consequential," Biden said. "They'll become more of a pariah in the world than they ever have been. And depending on the extent of what they do will determine what response would occur."

Biden's warning comes as Ukraine says it has retaken territory from Russia in a large counteroffensive operation while Putin is facing calls from some local Russian officials to resign as a result.