Dec. 27 (UPI) -- Russia's first hypersonic intercontinental ballistic missiles, described by Moscow as invulnerable to U.S. defenses, have been put into service, officials said Friday.
Russian Defense Minister Sergei Shoigu informed Russian President Vladimir Putin the first regiment of the nuclear-capable Avangard missiles had "assumed combat duty" as of Friday morning, state-run news agency Tass reported.