Russian Navy Yasen submarine Kazan
Russian Navy Yasen-class sub Kazan arrives at its permanent base on Russia's Arctic coast on June 1, 2021.
  • Russia's Yasen-class submarines have long been seen as a tough challenge for the US Navy.
  • They are quiet and able to carry torpedoes as well as Kalibr and Oniks cruise missiles.
  • A Russian shipbuilding official said that work is underway to arm them with Zircon hypersonic missiles.

The head of a top Russian shipbuilder revealed Monday that work is underway to arm some of Russia's most troubling guided-missile submarines with Zircon hypersonic weapons.