WASHINGTON (AP) — President Barack Obama has the votes for Senate ratification of a new arms control treaty with Russia, all but assuring a major foreign policy victory.

At least 10 Republicans have announced publicly that they will vote for the accord, with several Republicans coming on board Tuesday.

“I think it’s going to pass and more than just pass,” Bob Corker, one of the Republicans backing the treaty told reporters.

Ratification would be the latest of several political victories for Obama since his Democratic Party suffered major losses in congressional elections last month. It would deliver a foreign policy boost for his efforts to improve cooperation with Russia.

In the postelection congressional session, Obama has won overwhelming bipartisan passage of the tax deal he reached with Republicans and repeal of the ban on gays serving openly in the military — and the treaty was the centerpiece of his national security agenda.

Also declaring support for the treaty Tuesday, were Republican Sens. Lisa Murkowski and Lamar Alexander, the No. 3 Republican in the Senate, who bucked opposition by the top two Republicans in his announcement Tuesday.

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The Constitution requires two-thirds of those voting in the Senate to ratify the pact, and Democrats need at least nine Republican votes.

The White House and senior Democrats have pressed for a vote before January when Republicans increase their numbers in the Senate by five, raising doubts about the prospects for the treaty.

In signaling his support for the treaty, Alexander said it would leave “our country with enough nuclear warheads to blow any attacker to kingdom come.” He said he was reassured by a letter from Obama, in which he reiterated his commitment to modernizing the remaining nuclear arsenal with projected spending of $85 billion over 10 years.

“My administration will pursue these programs and capabilities for as long as I am president,” Obama wrote in letters to Republican Sens. Alexander and Thad Cochran and Democrats Dianne Feinstein and Daniel Inouye.

Senior Democrats were pushing for a decisive vote to cut off debate and set the stage for the final vote. Republicans and Democrats were discussing amendments to the accompanying resolution, not the treaty, that would deal with Republican problems with missile defense and build support for the agreement.

The United States and Russia negotiated the New START pact to cap nuclear weapons and restart weapons inspections in the spirit of U.S. efforts to reset the relationship between the former Cold War foes.

The White House has seen steady progress in its efforts to persuade Republican lawmakers. On Monday, Sen. Scott Brown announced he would support the treaty. In recent days, Brown had received a call from Secretary of State Hillary Rodham Clinton.

Republican Sen. Johnny Isakson, who also heard from Clinton, announced his support Tuesday.

Obama, who delayed his holiday vacation, lobbied senators by phone as he pressed to complete the treaty before January. Vice President Joe Biden also called lawmakers.

Bolstering Obama’s argument for quick action, Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, sent a letter to lawmakers reiterating support for the accord.

“This treaty enhances our ability to do that which we in the military have been charged to do: protect and defend the citizens of the United States. I am confident in its success as I am in its safeguards. The sooner it is ratified, the better,” Mullen wrote.

Defense Secretary Robert Gates, in a statement Tuesday, urged the Senate to ratify the pact this week. He said the treaty would “provide the necessary flexibility to structure our strategic nuclear forces to best meet national security interests.

Senate Foreign Relations Committee Chairman John Kerry, a Democrat, read parts of Mullen’s letter at a closed briefing.

Despite the letter, several conservative Republicans insist the treaty would restrict U.S. options on a missile defense system to protect America and its allies and argue that the accord has insufficient procedures to verify Russia’s adherence.

The treaty specifically would limit each country’s strategic nuclear warheads to 1,550, down from the current ceiling of 2,200. It also would establish a system for monitoring and verification. U.S. weapons inspections ended a year ago with the expiration of a 1991 treaty.

Copyright 2010 The Associated Press.