President Obama says Senate ratification of a pending arms treaty with Russia this year is a national security imperative.

Obama told reporters on Thursday the stakes for America are clear -- and high.

He spoke during a meeting with top aides and key backers of the pact, including former secretaries of state Madeleine Albright, James Baker and Henry Kissinger, and former defense secretaries William Cohen and William Perry.

The New START treaty would slash deployed arsenals on both sides by roughly a third. But its passage has been thrown into doubt by GOP calls to delay consideration until the new Congress convenes in January.

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