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 said Friday that Russia will continue to test and start mass-producing the hypersonic ballistic missile that it fired at Ukraine Thursday.

A new intermediate-range ballistic missile called Oreshnik used by Russia in a strike on Ukraine this month is a state-of-the art weapon that the West cannot intercept, President Vladimir Putin has said.

The new design is based on the previous RS-26 Rubezh ballistic missile, according to the Pentagon. Readers can get up to speed on what else is already known about the missile strike on the eastern Ukrainian city of Dnipro in The War Zone‘s initial reporting here.

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.