Russia sends 'doomsday nuke' torpedo capable of triggering tsunamis off of America's east coast to the Arctic for tests
- Washington said it is watching 'closely' as tests start for Poseidon 2M39 torpedo
- Underwater drone, which looks like a small submarine, has range of 6,200 miles
- Warhead designed to be detonated off enemy cities to cause radioactive floods
- Putin is keen for new updates as tests begin, with deployment possible in 2022
Washington has warned it is watching 'very closely' after satellite images have revealed the expansion of military bases, including an underground base which could be used for Poseidon 2M39.