US and Russian negotiators have been holding nuclear disarmament talks in Geneval in their last scheduled meeting before the presidents of both nations attend a summit in Moscow on July 6.
Russia and the US are at odds over a planned missile defense shield in eastern Europe
The ultimate aim of the disarmament talks negotiations is to replace the 1991 Cold War-era Strategic Arms Reduction Treaty (START) which expires on December 5, 2009. Both Obama and Medvedev have said they want "significant reductions" in their nuclear weapons arsenals.
Medvedev however has repeatedly said that further nuclear cuts could only come about if Washington addressed Moscow's "concerns" about deployment of the US missile defence shield in ex-Soviet states in eastern Europe.
US State Department spokesman Ian Kelly on Wednesday reiterated that Washington's desire to reduce nuclear arms is not linked to those missile defence shield plans. He said those plans would protect Europe and the US should Iran launch a rocket attack and are not intended as a threat to Russia.
Reaching a deal on disarmament talks is considered to be vital for rebuilding US-Russian relations, which sharply deteriorated in the final stages of President George W. Bush's administration.
Editor: Sonia Phalnikar