Russia's President Vladimir Putin has drawn a parallel between US plans for a missile shield in Europe and the Cuban missile crisis in 1962.
Mr Putin made his remarks after an EU-Russia summit, which was held in Portugal.
'Thank God, we do not have any Cuban missile crisis now and this is above all because of the fundamental way relations between Russia and the United States and Europe have changed,' Mr Putin said.
Mr Putin also said he was 'undecided' on his future political role, but stressed he would not change the constitution or alter the balance of power in Russia.
Read our special feature on the US plans to build a missile defence system in eastern Europe.
