Russian President Vladimir Putin on Wednesday observed exercises by Russia's strategic nuclear forces, the Kremlin said.
"The tasks envisaged during the training of the strategic deterrence forces were completed in full, all missiles reached their targets," a Kremlin statement said.
The Zvezda military news channel showed Defence Minister Sergei Shoigu telling Putin that the exercises were practising "delivering a massive nuclear strike by strategic offensive forces in response to an enemy nuclear strike".
Chief of Staff Valery Gerasimov told Putin the exercise involved Yars intercontinental ballistic missiles, submarines and Tupolev strategic bomber planes.
Russian officials have in recent weeks repeatedly accused Ukraine of planning to use a "dirty bomb" - a bomb laced with radioactive material. They have provided no proof for the allegation.
(Reporting by Reuters, Editing by William Maclean)
