President Barack Obama says any failure of the US Senate to approve a new arms control treaty with Russia could undermine American leadership on a host of other challenges it faces around the world.
A new Strategic Arms Reduction Treaty was signed by Mr Obama and President Dmitry Medvedev of Russia in April.
The treaty requires a two-thirds majority in the Senate to become law.
It would limit each country's strategic nuclear warheads and establish a system for monitoring and verification.
In a weekly radio address, Mr Obama said not ratifying the agreement would risk turning back the progress the United States has made in its relationship with Russia.
The BBC reports 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.
Mr Obama said failing to pass the treaty would hit US credibility in the eyes of other nations.
However, Senator Kit Bond, the most senior Republican on the Senate Intelligence Committee, has described the treaty as "giving Russia essentially a vote on our missile defence decisions".
Treaty details
The terms of the new treaty would restrict each nation to a maximum of 1550 deployed nuclear warheads - a cut of about 30% from a limit set eight years ago.
The treaty would limit to 700 the number of deployed ballistic missiles or nuclear bombers.
It would also establish a new mechanism for sending inspectors to the other country's nuclear sites.
The previous treaty expired in December 2009.
The BBC reports a vote is expected early next week.
