This is the first time Russia has used its so-called Oreshnik intermediate-range ballistic missile in combat. The launch also serves as a warning to the West.

Tit-for-tat moves this week included the use of American-made ballistic missiles to strike inside Russia, and new nuclear threats from Moscow. Neither appear to have influenced the war on the ground.

Russia fired an intercontinental ballistic missile during an attack on the Ukrainian city of Dnipro on Thursday, Kyiv's air force said, in what would be the first use in war of a weapon designed to deliver long-distance nuclear strikes.