The Pentagon says the Oreshnik is a tweak of Russia’s RS-26 Rubezh missile, an intercontinental ballistic missile (ICBM) that has been tested since 2011.

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

President Vladimir Putin warned that his forces could strike “decision-making centers” in the Ukrainian capital of Kyiv with new ballistic missiles as retaliation for attacks on Russia using Western missiles.