HONOLULU - President Obama and Russian President Dmitry Medvedev are hailing the Senate'sbetween their nations as a historic event.
The two leaders spoke by phone Thursday, a day after the Senate ratified the New START treaty. The White House says Mr. Obama and Medvedev agreed to continue cooperation on a range of critical issues.
Mr. Obama made the treaty's final passage a top national security imperative during the lame-duck session of Congress that ended Wednesday. The White House said it was crucial for the U.S. to ratify the treaty in order to maintain positive relations with Russia.
Mr. Obama spoke with Medvedev from Hawaii where he is vacationing with his family.
Russian legislators said they need until January to study a resolution accompanying the document before following suit.
Medvedev's spokeswoman Natalya Timakova said that when he signed the New START treaty with Mr. Obama, they agreed that the ratification process should be conducted simultaneously.
She said that Medvedev voiced hope that both houses of Russian parliament would ratify the pact, but added that they would need some time to analyze the Senate's conditions for its ratification before making their decision.
The New START treaty, signed by Mr. Obama and Medvedev in April, would limit each country's strategic nuclear warheads to 1,550, down from the current ceiling of 2,200. It also would re-establish a system for monitoring and verification which ended last year with the expiration of a previous arms control deal.
Legislators in the Kremlin-controlled parliament had said before the Senate landmark ruling on Wednesday that they would approve the treaty quickly after it is ratified in the U.S.
Lower house speaker Boris Gryzlov, however, told reporters Thursday that the Senate's ratification resolution contained some conditions and the legislators need to carefully study the text before making decision.
He added that the State Duma may ratify the pact Friday if the text of the treaty itself remained unchanged.
"If these conditions don't change the text of the treaty, we may pass a ratification bill even tomorrow," Gryzlov said.
He said that the house would need more time if it finds any changes in the body of the treaty.
Russian lawmakers might need to work on the treaty until next January, said Konstantin Kosachyov, the chairman of the international affairs committee in the State Duma. The resolution on the treaty's ratification "contains many interpretations that need a thorough study and a response of Russian lawmakers," he said.
Conservative Republicans said the pact would limit U.S. options on missile defense, lacked sufficient procedures to verify Russia's adherence and deserved more time for consideration.
The Obama administration has argued that the United States must show credibility in its improved relations with its former Cold War foe, and the treaty was critical to any rapprochement. The White House is also counting on Russia to help pressure Iran over its nuclear ambitions.
Republicans had tried to kill the treaty by forcing changes in its language that would have sent it back for negotiations with Moscow. Democrats sought to appease some Republican senators by letting them raise these issues in legislation accompanying the treaty that would not directly affect the pact.
On Wednesday, two such amendments, one on missile defense and one on funding for the U.S. nuclear arsenal, passed with support from both parties.
Konstantin Kosachev, the head of the Duma's foreign affairs committee, said that decision is conditioned on the analysis of the amendments.
"We realize that the process shouldn't be delayed, but we intend to work in such a way that it doesn't affect the quality," he said.
Kosachev said that the Duma may quickly approve the pact Friday without any conditions, or could decide to include some conditions of its own, which could delay the vote.
The treaty must also be ratified by the upper house, whose speaker Sergei Mironov said that could happen on Friday as well, if the Duma approves the document, the ITAR-Tass news agency reported.
Russian Foreign Minister Sergey Lavrov said Thursday that Moscow was still waiting for the official text of the resolution and refused to comment on issues raised by Republicans in the Senate resolution.
"The specific content of the Senate resolution will naturally determine the wording that our legislators will put in the Russian ratification bill," Lavrov said at a briefing.
Retired Gen. Vladimir Dvorkin, who helped negotiate previous arms deals with the United States, predicted that the Kremlin-controlled parliament will quickly ratify the New START.
"This treaty is important for the Russian leadership because it formally preserves the nuclear balance with the United States, the last attribute of a superpower," Dvorkin said, according to the Interfax news agency.