The Russian Ministry of Defense said it was "amazed" by London's response.
Black box recorders still missing from plane that plunged into Mediterranean with 66 on board.
Pyongyang wants the U.S. to halt its military exercises with South Korea in return.
South Korea, experts fear the North may conduct its fifth nuclear test 'at any time.'
Missile could pose a new threat to South Korea, Japan and the United States, a military expert said.
The move is part of ongoing military combat readiness drills.
Hewn out of a mountain, Olavsvern, Norway, is one of the most impregnable hideouts in the world.
An operation has been launched after a periscope was spotted off near Britain's Faslane nuclear base
Russia's top navy admiral plans to strengthen forces in Crimea and the Arctic over the next 15 years
The ship's presence was preceded by the appearance of two Russian bomber jets in Portuguese as the Finnish president warned of a new Cold War
Sweden, Finland, Latvia, Lithuania and Estonia are all reporting massively increased military trespassing by the Russian military