Russia has test-launched its new intercontinental ballistic missile - which Vladimir Putin has boasted can overcome any defence system.
The Sarmat missile was launched from Plesetsk in the country's northwest and hit targets in the Kamchatka Peninsula in the far east.
And the Russian president has said the weapon would provide "food for thought" for those who try to threaten his country.
"The new complex has the highest tactical and technical characteristics and is capable of overcoming all modern means of anti-missile defence," he said.
"It has no analogues in the world and won't have for a long time to come."
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Putin says said the weapon would provide 'food for thought' for those who try to threaten his country
Commander issues 'final message' from steel plant - Ukraine live updates
The Sarmat is a new heavy intercontinental ballistic missile which Russia is expected to deploy with ten or more warheads on each missile, according to the US Congressional Research Service.
The Russian defence ministry was quoted by the Interfax news agency as saying: "The launch's objectives were fully attained. The planned performance specifications were confirmed throughout all phases of the flight."
It added that a regiment of Russia's Strategic Missile Forces stationed in the Krasnoyarsk territory is being prepared to be armed with the new missile.
The Pentagon insisted Russia had informed the US ahead of test and that it saw it as "routine and not a threat to
the United States".
It comes as Russian forces increased their push towards diehard Ukrainian defenders holed up at a Mariupol steel plant.
There have been desperate new efforts to open an evacuation corridor for trapped civilians in the ruined city, a key battleground in Moscow's drive to seize the country's industrial east.
Ukraine's military said Moscow continued to mount attacks across the east, probing for weak points in the Ukrainian defensive lines.
Russia said it launched hundreds of missile and air attacks on Ukrainian targets, including concentrations of troops and vehicles.
The Kremlin's stated goal is to capture the Donbas, the mostly Russian-speaking eastern region that is home to coal mines, metal plants and heavy-equipment factories vital to Ukraine's economy.
Detaching it would give Russian President Vladimir Putin a badly needed victory two months into the war.