The Russian and U.S. presidents signed a preliminary agreement on Monday to cut their countries' nuclear arsenals to 1,500-1,675 operational warheads within seven years after a new arms reduction treaty comes into force, RIA Novosti reported.
The framework deal agreed during Kremlin talks between Dmitry Medvedev and Barack Obama during the U.S. leader's first visit to Russia sets guidelines for a new treaty to replace the START 1 pact, due to expire in December.
"Within seven years after this treaty comes into force, and in the future, the limits for strategic delivery systems should be within the range of 500-1,100 units and for warheads linked to them within the range of 1,500-1,675 units," the framework agreement said.
Speaking at a news conference after the summit, Medvedev said the treaty would be a "basic element of our mutual security."
Obama said that they had taken "important steps forward to increase nuclear security and to stop the spread of nuclear weapons."
"We have signed a joint understanding for a follow-on treaty on the START agreement which will reduce our warheads and delivery systems by up to a third from our current treaty limitations. This legally binding treaty will be completed by the end of this year," he said.
The framework document says the new treaty would be in effect for 10 years and should include data exchange structures, inspections and measures to build confidence and improve transparency.
The treaty would not cover cooperation in this sphere with third countries.
The framework agreement says the new treaty should highlight a link between strategic offensive and defensive weapons, reflecting Russian concerns about Washington's plans to open a missile base and a radar in Central Europe.
At the news conference, Obama acknowledged the persisting difference on missile defense, and reiterated that the shield elements would "deal with a missile coming in from Iran or North Korea, or some other state."
"There is no scenario from our perspective in which this missile defense system could provide any protection against a mighty Russian arsenal," Obama told reporters. "And so in that sense we have not thought that it is appropriate to link discussions of a missile defense system designed to deal with a entirely different threat, unrelated to the kinds of robust capabilities that Russia possesses."
Obama, who has shown less interest in the shield elements in Europe pursued by his predecessor, has said he could review the plans.
Obama said he sought cooperation with Russia in advancing a system that would protect them from stray missiles, but added "it is going to take some hard work" as "it requires breaking down long-standing suspicions."
The presidents announced several other deals as part of their pledges "to reset" ties which were strained under the George W. Bush administration.
They include a deal allowing U.S. military transits via Russia into Afghanistan, and an agreement to set up a commission to step up cooperation in energy, business and scientific ties, and efforts against terrorism and drug trafficking. The commission is to be headed by the presidents.
They also agreed to resume military cooperation suspended after Russia's war with Georgia last August, one of the issues that plunged relations between Moscow and Washington to a new Cold War low.
Medvedev said the talks with Obama set a new tone of Russian-American relations and were the start of a mutually beneficial cooperation.
"Speaking of the first day of talks and their results, I would say they were the first step toward invigorating a cooperation both states would benefit from," he said.