Robert Gates, the US defence secretary, has arrived in Moscow to discuss Washington's European missile plans with Vladimir Putin, the Russian president.
Russia has criticised US plans to station missile defence system sites in Poland and the Czech Republic, saying they could impact its security.
Washington wants to place 10 "interceptor" missiles in Poland and a radar in the Czech Republic at a cost of $3.5 billion.
Ahead of Gates's visit, the US assembled a package of incentives aimed at allaying Russian fears, said officials travelling with the defence secretary.
These incentives, presented last week, include an offer to share missile warning data and co-operate in developing and testing missile defence technology with the Russians.
"We outlined a series of areas where we might be able to co-operate with Russia and this involves both sharing of information and potentially of technology," said a senior administration official.
"It includes things like sharing sensor data for early warning, common research and development, testing of various components of systems," said the official.
But the Pentagon intends to move forward whatever the response, officials said.
"We're going to continue to make this effort with Russia but we're also very clear, whether Russia co-operates with us or not is really up to Russia," a US official said on Sunday.
'No interference'
The US insists that existing defences need to be extended to protect against attack from Iran and North Korea and says its missile shield plans are not directed against Russia.
However, critics say the US could eventually equip the sites with offensive weapons aimed at Russia.
Germany has said Washington must work to ease Russian concerns, although the Czech Republic and Poland have said Moscow has no right to interfere.
Igor Ivanov, secretary of Russia's security council said he held little hope the discussions would yield a quick resolution on the missile defense dispute.
"We would want to hope that Washington listens to our views and concerns, although I am not much of an optimist on this issue," he said.