Published: Dec 01, 2010 9:34 PM EST
Updated: Dec 01, 2010 6:34 PM EST

WASHINGTON (AP) - President Barack Obama turned to former Secretary of State Colin Powell for help Wednesday in getting a stalled nuclear weapons treaty with Russia through the Senate.

Obama invited the retired four-star Army general and former Joint Chiefs of Staff chairman to the White House a day after stressing the need for the Senate to ratify the New START treaty by the end of the year.

However, one top Republican said Powell's endorsement was unlikely to sway him to vote for the treaty.

"I respect Secretary Powell a lot, but this is a matter of us doing our job, doing our due diligence," Sen. John Cornyn, R-Texas, said.

Arizona Republican Sen. John McCain, whose vote on the treaty would be critical for the White House, said Powell's endorsement didn't come as a surprise.

Powell, who served as secretary of state under former President George W. Bush, endorsed Obama in the presidential election over McCain.

The president has said the treaty is crucial to U.S. national security, and he appealed anew for its approval Tuesday in a meeting with bipartisan congressional leaders. But leading Republican lawmakers argue that there are more pressing priorities to address during the lame-duck session of Congress and the GOP has threatened to block any Senate floor business other than budgetary or tax issues during the lame duck session.

However, White House officials were cautiously optimistic Wednesday that momentum for passing START was building after some Republicans appeared to leave the door open for ratification. Officials specifically pointed to comments from Sen. George Voinovich, R-Ohio, and McCain, who both indicated they'd like to finish work on the treaty this year.

"We still think it's going to happen," White House spokesman Robert Gibbs said.

Sen. Bob Corker, R-Tenn., a member of the Foreign Relations Committee, also indicated that the administration has addressed some of their concerns, including several matters raised by Sen. Jon Kyl, R-Ariz., about modernization of the remaining nuclear arsenal and sufficient funds for safeguarding the stockpile.

The pact would reduce the limits on strategic warheads held by the United States and Russia and would set up a system so each could inspect and verify the other's arsenal.

Russian Prime Minister Vladimir Putin is warning that his country would build up its nuclear forces if the U.S. doesn't ratify the treaty.

In an interview to be broadcast Wednesday on CNN, Putin said that if the treaty isn't ratified, "we'll have to react somehow," including deploying new nuclear technology. Putin said it would take "a very dumb nature" for lawmakers to block the treaty.

Powell is the latest in a string of current and former national security officials brought in to bolster the need to ratify the treaty.

Last month, Obama met at the White House with what he called "some of the most able statesmen from both parties" to voice their support for START. They included former secretaries of state Madeleine Albright, James Baker III and Henry Kissinger, former defense secretaries William Perry and William Cohen and former National Security Adviser Brent Scowcroft.

During a NATO summit in Portugal, Obama also secured the backing of several Eastern European nations, easing Voinovich's concerns that the treaty would undermine the confidence of allies in Central and Eastern Europe.

The White House said Obama and Powell would also discuss education and efforts to reduce the high school dropout rate, an issue Powell has been actively involved in since leaving government.

--- Associated Press writer Donna Cassata contributed to this report.

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