Russian Foreign Minister Sergei Lavrov has said no agreement has been reached with the US over its plan to base parts of a missile defence system in Europe.
Sergei Lavrov said the US had heeded Russia's concerns
He said Russia continued to oppose the use of facilities in Poland and the Czech Republic after talks in Moscow.
But his US counterpart, Condoleezza Rice, stressed the countries continued to work together on a range of issues.
On Monday, Russian President Vladimir Putin spoke of the prospect of better relations between the two nations.
Mr Putin said he had received a "serious document" from President George W Bush that might help resolve a number of problems, including missile defence.
After talks with Ms Rice and Defence Secretary Robert Gates in Moscow on Tuesday, Mr Lavrov said the US had reiterated its intention of deploying missile defence facilities in eastern Europe, and that his government still opposed those plans.
Washington wants the shield to destroy ballistic missiles potentially coming from "rogue" states such as North Korea and Iran.
Its current plans would see some interceptor missiles based in Poland and an associated radar built in the Czech Republic.
Moscow has objected to the proposal, saying the missiles and radar could threaten its own defences and the facilities in eastern Europe expanded in the future.
Nevertheless, Mr Lavrov said the US had made "important, useful proposals" aimed at allaying some of Russia's concerns at their meeting.
"The American side, as far as we understand, has heeded our concerns," he added. "We agreed to continue consultations to study the proposals received today."
Ms Rice agreed both sides had held "useful" discussions on missile defence.
"When we have differences, we can talk about them in an atmosphere of mutual respect," she added.
Following Monday's discussions with Mr Putin and President-elect Dmitry Medvedev, Mr Gates suggested a deal could be struck on missile defence before Mr Bush left office in January 2009.
"The environment in our meetings was positive," Mr Gates said. "Whether that leads to a positive conclusion remains to be seen."
Mr Putin, who steps down next month, said there were "enough problems" to discuss but that some issues could be considered resolved. He did not elaborate.
Referring to the letter he had received from Mr Bush, the Russian president said: "If we manage to agree on its main provisions, we will be able to say that our dialogue is progressing successfully".
For his part, Mr Medvedev said that while differences remained between the two former Cold War foes, "there is a will to move forward".
The atmosphere ahead of this week's talks was soured by an ill-tempered verbal exchange.
A US state department document released last week highlighted reports of widespread human-rights abuses in Russia.
The Kremlin dismissed it as a "hackneyed collection of claims" and accused Washington of "double standards".