Russia’s widespread overnight attack targeting critical energy infrastructure facilities in Ukraine was a response to strikes on Russian territory using US-made ATACMS missiles, President Vladimir Putin said Thursday.

Russia named the missile the Oreshnik, or hazel tree, and said it is impossible to intercept it with air defenses.

The Ukrainian Air Force claims that Russia launched a conventionally armed intercontinental ballistic missile (ICBM) today at the city of Dnipro, in the center of the country. In either case, the act is unprecedented for the war in Ukraine and it would mark the first use of either one of these types of weapons in combat anywhere.