Since debate began last Wednesday, some Republicans have sought to defeat the treaty with delay and "treaty-killer" amendments to the preamble or text by filing more than seventy amendments. But the Democrats garnered 11 Republican votes on Tuesday to end debate and bring full vote on the treaty.

If delayed until early January when the new Congress opens, the pact is sure to face a dim outlook in the Senate as the Democrats' strength there is reduced from 58-42 to 53-47.

Russian Foreign Minister Sergey Lavrov told the Interfax news agency on Monday that ratification of the arms pact would "give a powerful impulse" to Russia-U.S. ties.

The Russian lower house of parliament, the State Duma, said it may follow suit before the end of the year if the treaty is passed in Washington.

"The treaty will strengthen U.S.-Russia relations, which is essential for our efforts to prevent Iran from getting the bomb and to build a strong international coalition to stop nuclear proliferation worldwide," Burt said in his statement.