Missile defense emerged last year as a source of contention between Russia and the United States. The Kremlin said it viewed U.S. missile defense plans in Eastern Europe as a threat to the regional balance of power. The White House said regional deterrence is needed against rogue regimes like Iran and North Korea.
Medvedev told CNN last weekend that missile defense issues were problematic for Moscow.
"There are no easy solutions in terms of anti-missile defense. There is no flexibility," he said. "We have not changed our previous positions -- the United States has one opinion and the Russian Federation, unfortunately, has a different opinion."
U.S. President Barack Obama said last year he'd have more flexibility to deal with missile defense issues following the campaign season, which ended with his re-election in November.
The Russian government says it wants assurances the United States won't direct any Eastern European missile defense system against its interests.
"We do not want next generations of politicians in 2019 or 2020 to take decisions which would open a new page in the arms race," said Medvedev.