Moscow considers Washington's plans to deploy a tracking radar in the Czech Republic and interceptor missiles in Poland to be a threat to Russian security. The United States has argued the facilities are necessary to guard against the threat of missile attacks from states such as Iran.
"I am pleased that our American partners are showing willingness to discuss this issue rather than take a stubborn stance and deploy [the shield] no matter what," Medvedev said at a meeting with A Just Russia party activists.
"Missile defenses [in Europe] are not the best idea proposed by the previous U.S. administration... it is an idea that was adopted without consulting certain NATO and EU institutions," he said.
Top Russian officials have repeatedly expressed their hope that the new U.S. administration will not follow through with the plans, and Medvedev said after talks with U.S. President Barack Obama in April that both countries would make every effort "to find a way out of this difficult situation."
Medvedev also said that Russia's initiative on a new pan-European security treaty was being cautiously received in Western countries.
"Of course, our European colleagues are trying to study it under a microscope, but this is understandable, and we are ready for discussions," he said. "It is a good idea, and it should be promoted."
Medvedev proposed the idea of a new European security treaty in Berlin last June, saying it should include peaceful conflict prevention and settlement arrangements, confidence building measures, and arms control mechanisms.