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.