Russian president Dmitry Medvedev has said his armed forces must prepare to counter US missile defence plans.
Mr Medvedev said that even though diplomatic efforts were continuing, Russia must be ready to mount a military response to the US-led Nato missile shield by 2017-2018.
Nato has said it wants to cooperate with Russia on the shield, intended to fend off the Iranian missile threat, but it has rejected Russia’s proposal to run the shield jointly.
Without a Nato-Russia cooperation deal, Mr Medvedev has sought guarantees from the US that any future missile defence is not aimed at Russia. He has threatened to aim missiles at the US shield if no agreement is reached.