Published: Dec 14, 2010 10:48 PM EST
Updated: Dec 14, 2010 7:48 PM EST

WASHINGTON (AP) - The Senate Democratic leader said Tuesday he will press ahead on a U.S.-Russia nuclear treaty, President Barack Obama's top foreign policy priority, despite strong opposition from some Republican lawmakers.

The White House has signaled that Obama would delay his holiday vacation to ensure ratification of the treaty that would limit both nations' nuclear warheads and establish a system for verification. Congress is struggling to complete several top pieces of legislation, including a tax cut bill and a measure to keep the government running, in the final week of a lame-duck session. The treaty is one of the items on the Senate Democrats' must-do list.

Senate Majority Leader Harry Reid, D-Nev., told reporters, "We are not going to walk away from any of the work that we have to do." He said he would move for a vote on the treaty and was confident he had the numbers to ratify it.

Jim Manley, a spokesman for Reid, had said earlier that the Senate could begin debate as early as Wednesday.

Obama has pushed hard for ratification of the treaty, which has the backing of former Presidents George H.W. Bush and Bill Clinton as well as secretaries of state and defense for Republican and Democratic administrations. But several Republican senators have expressed concern that the treaty would limit a missile defense system and have suggested there isn't enough time in the lame-duck session to give the pact the attention it requires. Twenty-two Republican senators signed a letter Dec. 2 calling for consideration of the treaty to be delayed until next year.

Obama has gained support for the pact in recent days and is within striking distance of the 67-vote threshold required in the Senate for ratification. Maine's two Republican senators, Olympia Snowe and Susan Collins, indicated their support last week, and at least six other Republicans have signaled backing for the treaty, although with some qualifications. All 58 senators in the Democratic caucus are expected to back the treaty.

"I believe we can pass the START treaty if we get a chance to do it," Foreign Relations Committee Chairman John Kerry, D-Mass., said Tuesday.

Several Republicans have opposed quick action on the treaty and could thwart Reid's effort to move forward with various procedural obstacles or amendments.

The administration is pressing to complete the treaty this year because the political calculation becomes more difficult in the next Congress, when Republicans increase their numbers in the Senate.

White House spokesman Robert Gibbs said Obama made the nuclear treaty with Russia a top priority during the lame-duck session in part because he believes there are more than enough votes in the Senate to support ratification.

"I don't know why you'd put off until next year what you can accomplish this year," Gibbs said. Obama signed the treaty with Russian President Dmitry Medvedev in April. The treaty would allow each country 1,550 strategic warheads, down from the current ceiling of 2,200.

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