Russia's President Vladimir Putin warned the United States against deploying new missiles in Europe, threatening to retaliate in kind by targeting Western capitals with his own new weaponry.
Delivering a state of the nation address, Putin said the US abandoned a key arms control pact - the 1987 Intermediate Range Nuclear Forces treaty - to free its hands to build new missiles and tried to shift the blame for the move on Russia.
Many analysts say abandoning the treaty effectively signals the start of a new arms race.