President Barack Obama has renewed his call for US senators to ratify an arms control treaty with Russia before the Democratic-led Congress breaks up.
In his weekly address, Mr Obama said the "safety and security of America" was at stake.
The US and Russian presidents signed the new Strategic Arms Reduction Treaty (Start) in April, but ratification has been delayed by disagreements.
The treaty requires a two-thirds majority in the Senate to become law.
That means that the Democrats need two independents and a number of Republicans to vote in favour of ratification.
Some Republicans had tried to delay the debate on ratification until January, when a new-look Congress will include more Republican senators.
The treaty is a key part of Mr Obama's efforts to "reset" relations with Russia.
But Republicans have raised a number of concerns, including whether the treaty would allow the modernisation of America's nuclear arsenal.
One senior Republican, Senator Kit Bond, said the treaty would give "essentially a vote on our missile defence decisions". BBC News
