Barack Obama has assured Russian president Dimitry Medvedev that a US Senate vote on the new Strategic Arms Reduction Treaty (Start) should happen this week.
"I reiterated my commitment to getting the Start treaty done during the lame-duck session and I've communicated to Congress that it is a top priority," the US president said.
Mr Obama made the assertion at a breakfast with his Russian counterpart on the sidelines of the Asian-Pacific Economic Co-operation forum in Yokahama, Japan.
The nuclear arms treaty is pending in the Senate, which is due to return this week for a post-election session. There has been resistance to the pact, principally from minority Republicans.
Mr Obama declined to answer a question about whether his administration was putting more money on the table to maintain the US nuclear stockpile in order to win Republican support for the pact.
He also said he believed Mr Medvedev was reforming the political system in Russia and moving the country forward. He said he supported Mr Medvedev's pursuit of membership in the World Trade Organisation - a point the Russian leader reinforced as he and Mr Obama appeared briefly before reporters and camera crews.
Both leaders spoke of the close relationship they had and called each other friends and partners.
"It has been very pleasant for me to have this meeting and discuss a whole range of bilateral and multilateral issues with my colleague," said Mr Medvedev.
"Indeed, we have a very good relationship. We understand each other very well. It's very important to attain agreement on a whole range of issues."