A Russian nuclear attack would "almost certainly" trigger a military response from Kyiv's friends, a senior NATO official said.
There would be "unprecedented consequences" should Putin turn to nuclear weapons, they said, per Reuters.
There would be "unprecedented consequences" should Russian President Vladimir Putin turn to nuclear weapons, the unnamed NATO official said, according to Reuters.
A Russian nuclear attack would "almost certainly be drawing a physical response from many allies, and potentially from NATO itself," the official warned.
"I do not believe that a nuclear response is something that the United States and its allies should be placing on the table.