"We discussed issues on which no agreement has so far been reached," Sergei Lavrov told a news conference after talks with U.S. Secretary of State Condoleezza Rice, Defense Secretary Robert Gates, and Russian Defense Minister Anatoly Serdyukov.
The U.S. plans to deploy a missile shield in Poland and the Czech Republic, which it says will provide defense against 'rogue states' such as Iran, but which Moscow views as a direct threat to its own security.
Gates told reporters the talks had given the U.S. side "the chance to elaborate on a number of confidence-building measures to provide assurance to Russia that our missile sites and radars would not constitute a threat to Russia."
He said specific proposals were being finalized in writing.
"The full range of what we are prepared to discuss with the Russians really is just now being put down on paper so the Russian side will not receive this in writing until the evening. I would expect that we will hear back reasonably quickly," he said.
Lavrov called the U.S. proposals to ease Russian concerns "useful and important."
"We appreciate that the United States has acknowledged our reasonable concerns, and made proposals to ease them," the minister said.
Washington earlier offered to give Russian officials access to the proposed sites to ensure the radar is not targeted at Russia and interceptor missiles are kept non-operational until Iran's long-range missiles have been proved as a threat.
