Secretary of the National Security and Defense Council of Ukraine Oleksiy Danilov believes that if Russia uses tactical nuclear weapons, "the world should react differently."

"In my opinion that such an aggressor as Putin should have been stopped back in 2008," he said on the air of the telethon on Tuesday.

"God forbid, they dare to do it. Then the world would react differently. Then the sanctions should be hellish so that it ends as quickly as possible," Danilov said.

He believes that in this case "it will be a completely different war, different responsibility, different actions of our partners."