Experts say the new agreement, designed to replace the 1991 Strategic Arms Reduction Treaty, will reduce strategic nuclear warheads by almost a third, to about 1,550 on each side, and halve the number of delivery vehicles – missiles, bombers and submarines – to 700 for each country.
The US and Russia still deploy more than 90 per cent of the world's nuclear weapons; the US currently around around 2,150 strategic warheads while Russia reportedly maintains about 2,600. Both sides have thousands more in storage, or awaiting dismantlement under previous arms control deals.
The treaty will still need to be ratified by a two-thirds vote the US Senate, as well as by Russia's upper and lower houses of parliament. Concerns have been raised on both sides about the treaty, which will slash strategic arsenals to their lowest levels since the superpower arms race began in earnest in the 1960s.
Political victory for Obama, Medvedev
Obama noted that the new treaty will continue the warming trend in relations with Russia that his administration began, a sentiment widely echoed in Russia. Russian arms control experts say it's been a long time coming, after nearly a decade in which serious dialogue about strategic stability lapsed, while tensions and mistrust between Washington and Moscow spiked to post-cold war highs.