The US Senate ratified Wednesday a landmark nuclear arms control treaty with Russia, handing President Barack Obama a signal diplomatic and political victory after a months-long battle.

Lawmakers voted 71-26 in favor of the new Strategic Arms Reduction Treaty (START), easily clearing the two-thirds majority needed to approve the pact, which Obama had made a lynchpin of efforts to "reset" relations with Moscow.

Russian Foreign Minister Sergei Lavrov welcomed the move but said Moscow needed time to "study" the US documents before doing the same, noting the text had been amended since its initial draft.

Prior to approving the treaty, lawmakers attached non-binding amendments to the resolution of ratification technical document to recommit Washington to deploying a missile defense system, modernizing its nuclear arsenal, and seek new talks with Russia on curbing tactical nuclear weapons.

The ratification was a signal of "efforts to ensure the dynamic development of bilateral relations" between the former Cold War foes, Lavrov was quoted as saying by the Interfax news agency.

US President Barack Obama savored Senate approval of the START treaty shortly after signing a historic law to enable gays to serve openly in the US military for the first time in history, another unlikely triumph in the waning days of his Democratic allies' control over the polarized Congress.

A Republican romp in November 2 elections means the White House's foes, who battled tooth and nail to stall both presidential priorities, will control the House of Representatives and have a more robust Senate minority come January.

The START treaty, which must still be ratified by Russia's parliament, restricts the former Cold War foes to a maximum of 1,550 deployed warheads each, a cut of about 30 percent from a limit set in 2002, and 800 launchers and bombers.

It would resume mutual on-the-ground inspections of nuclear facilities, which lapsed when the accord's predecessor expired in December 2009.

"This is the most significant arms control agreement in nearly two decades and it will make us safer and reduce our nuclear arsenals along with Russia," Obama told a year-end press conference.

"The strong bipartisan vote in the senate sends a powerful signal to the world that Republicans and Democrats stand together on behalf of our security."

German Foreign Minister Guido Westerwelle hailed the treaty's ratification, saying it "sets the course for a decade of disarmament and affirms President Obama's vision for a world free of nuclear weapons."

He urged Russia to move "quickly" to ratify the text as well.

"A successful conclusion of 'New START' would be a quantum leap for the worldwide efforts at nuclear disarmament and a clear signal that both leading nuclear powers take seriously their disarmament obligations," he added.

UN Secretary-General Ban Ki-moon said the Senate's rubber stamp would bolster non-proliferation and disarmament efforts.

Ban "hopes that the Russian Federation and the United States build upon this momentum and continue to engage in follow-on measures in order to achieve deeper reductions in their nuclear arsenals," his spokesman said.

After a relentless courtship by Obama, Vice President Joe Biden and top US military commanders, 13 Republicans backed the treaty, bucking leaders eager to hand the president a major defeat, and no Democrats broke ranks.

"I am confident that our nation's security, and that of the world, will be enhanced by ratifying this treaty," said Senate Foreign Relations Committee Chairman John Kerry, the accord's chief Democratic patron in Congress.

Kerry -- who, with the panel's top Republican, senator Richard Lugar, steered the accord through a difficult and at times bitter debate -- echoed White House arguments that the pact will help efforts to confront Iran and North Korea.

The accord "is not simply an agreement to address the lingering dangers of the old nuclear age. It is an agreement that will give us a crucial tool to combat the threats of this new nuclear age," he said moments before the vote.

Biden presided over the session -- a vice presidential prerogative -- and US Secretary of State Clinton milled about with senators ahead of the vote.

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