U.S. Senator John Kerry (D-MA) (L) and Senator Richard Lugar (R-IN) address a news conference after the Senate ratified the START nuclear arms reduction treaty at the US Capitol in Washington, December 22, 2010.

The U.S. Senate voted on Wednesday to ratify a nuclear arms treaty with Russia, delivering President Barack Obama his top foreign policy goal as the lame-duck Congress session draws to an end.

The victory came by a margin of 71-26 in the 100-member chamber, more than the two-thirds of majority of votes needed.

Hours before the Senate passed the new Strategic Arms Reduction Treaty (START), White House spokesman Robert Gibbs told reporters that the pact's obituary "has been written more times than I could care to remember. None of that was easy and none of what has to happen going forward is easy."

"The Senate's action today was imperative for national security, " said Richard Burt, a chief negotiator on the original START treaty, in a statement. "The new START treaty will continue the important process of reducing and monitoring U.S. and Russian Cold War arsenals, and pave the way for the critical next step -- bringing all nuclear weapons countries into multilateral nuclear arms negotiations for the first time in history."

The Obama administration envisages the accord as the first step in a continuing process of reducing nuclear weapons, 90 percent of them are owned by the U.S. and Russia. Russian President Dmitry Medvedev has agreed in principle to work toward further cuts.

Obama also sees the treaty as the centerpiece of his efforts to reset relations with Russia, and has delayed his holiday vacation to guide it through before the Congress breaks for holidays.

To line up support at home since the post-election Congress opened in mid-November, the president had met with heavyweights from the military and foreign communities, used his weekly address to appeal to the public, and written and made calls to like-minded yet wavering Republican senators.