WASHINGTON: US President Barack Obama scored a major foreign policy victory as an overwhelming majority in the Senate approved his nuclear arms control pact with Russia. Thirteen Republicans broke with their top two leaders and joined 56 Democrats and two independents in surpassing the necessary two-thirds vote to approve the New START treaty 71-26 Wednesday. Obama praised the strong bipartisan vote for a treaty he described as the most significant arms control pact in nearly two decades. “This treaty will enhance our leadership to stop the spread of nuclear weapons and seek the peace of a world without them,” he told reporters at a White House news conference. The accord, signed by Obama and Russian President Dmitry Medvedev in April, must still be approved by Russia. Russian Foreign Minister Sergey Lavrov said Moscow welcomed the vote but still needed to study the Senate resolution. The pact would restart onsite weapons inspections as part of a system for monitoring and verification. It would also limit each country's strategic nuclear warheads to 1,550, down from the current ceiling of 2,200. Vice President Joe Biden presided over the Senate vote and announced the vote as Secretary of State Hillary Rodham Clinton observed from the Senate floor. Both former senators had lobbied furiously for the treaty's approval. “The question is whether we move the world a little out of the dark shadow of nuclear nightmare,” Foreign Relations Committee Chairman John Kerry, a Democrat, said before the historic tally. Calling the treaty a national security imperative, Obama had pressed for its approval before a new, more Republican Congress assumes power in January. In recent days, he had telephoned a handful of wavering Republicans, eventually locking in their votes. World leaders also hailed the Senate vote, with UN Secretary General Ban Ki-moon calling it “a firm and clear message in support of nuclear disarmament and nonproliferation.” The ratification was a turnaround for a treaty whose fate was uncertain just a month ago. Conservatives railed that the pact would limit US options on missile defense, lacked sufficient procedures to verify Russia's adherence and deserved more time for consideration than the postelection session. – Associated Press Main elements Here are some key provisions of the treaty as well as background leading to the present treaty: NEW START: n Each side agrees to reduce its deployed nuclear warheads to no more than 1,550 within seven years. That is up to 30 percent lower than the 2002 Moscow Treaty and down nearly two-thirds from the 1991 START 1 treaty. n Each side agrees to limit its intercontinental ballistic missile launchers, submarine ballistic missile launchers and heavy bombers to no more than 800, whether deployed or not. n Each side agrees to deploy no more than 700 intercontinental ballistic missiles, submarine ballistic missiles or heavy bombers. BACKGROUND: The START Treaty, originally signed in July 1991 by George Bush and Mikhail Gorbachev, led to the largest bilateral reductions of nuclear weapons in history. n It was the result of nearly a decade of sporadic talks between the United States and the Soviet Union in the final years of the Cold War. n It entered into force in 1994 and by Dec. 5, 2001 its limits had been met by both sides. It was due to expire on Dec. 5, 2009, but the US and Russia decided to extend it. A START II Treaty, signed by Presidents George Bush and Boris Yeltsin in 1993, never entered into force because of rows between Washington and Moscow. n President Barack Obama and President Dmitry Medvedev signed the new strategic arms agreement in April 2010.