The Kremlin announced Friday it was shifting the RS-28 Sarmat, a nuclear-capable missile unofficially called the "Satan II," to combat readiness mode.

Yury Borisov, head of the Roscosmos State Space Corp., confirmed the move on state television in the wake of an escalation in nuclear-themed rhetoric following Ukraine's recent territorial gains.

Russian President Vladimir Putin revealed last year that the missiles would be deployed for combat readiness sooner rather than later, Reuters reported.

"The new complex has the highest tactical and technical characteristics and is capable of overcoming all modern means of anti-missile defense. It has no analogs in the world and won't have for a long time to come," Putin said at the time.

"This truly unique weapon will strengthen the combat potential of our armed forces, reliably ensure Russia's security from external threats, and provide food for thought for those who, in the heat of frenzied aggressive rhetoric, try to threaten our country," he added.

Roscosmos-operated Makeyev Rocket Design Bureau developed the Sarmat intercontinental ballistic missile in the late 2000s. It is replacing the R-36 ICBM, also known as Satan I.

The Center for Strategic and International Studies noted that the missile is 116 feet long, weighs 220 tons, and can carry up to 15 light nuclear warheads on multiple independently targetable reentry vehicle payloads.

It also has an estimated range of between 6,200 and 11,180 miles.

RS-28 Sarmat's deployment comes as Ukraine has  broken through Russia's front lines after months of agonizing stalemate. Kyiv expects to make even more gains as Western tanks and rocket launchers pour in.

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