Russia is set to test its biggest ever nuclear missile which is powerful enough to destroy the whole of the UK, Texas or France with a single strike.
The so-called Satan 2 intercontinental ballistic missile could deliver about a dozen nuclear warheads of 40 megatons - 2,000 times as powerful as the atom bombs dropped on Hiroshima and Nagasaki in 1945.
President Vladimir Putin's Defence Ministry plans to test two RS-28 Sarmat super nukes at the remote Plesetsk Cosmodrome before the end of the year, it was reported.
The 100-tonne weapons - which could enter service as early as 2019 - will make the bombs dropped on Japan look like “popguns”, experts have said.
Russia claims the missiles can "beat any defences" as it seeks to replace its arsenal of SS-18 Satan weapons.