Russia has warned it is set to test a missile that can travel at a speed of 750km/h and can reach the UK in just six minutes.
The Behemoth Satan-2 missile is set for a missile test, with a proposed launch for the intercontinental ballistic missile listed sometime before the end of December.
The announcement comes in the face of potential delays in the deployment of the "unstoppable" hypersonic missile, known to those in Vladimir Putin's Moscow as the Sarmat.
Concerns over the revelation that Russia may launch another test mean the Satan-2 missile could become fully operational next year.
A statement from Russia's Defense Ministry said: "Sarmat flight design tests may continue before the end of this year with a second test launch potentially being carried out."
Tests for the Sarmat missile were planned for June this year, with the Kamchatka region told to prepare for a launch, but that never happened.