U.S. Secretary of State Condoleezza Rice and Czech Foreign Minister Karel Schwarzenberg signed the deal covering the terms for the deployment of the radar, which still requires final approval from the Czech parliament. (VIDEO)
"Given this situation, the Russian side will obviously have to take appropriate measures to compensate for the growing potential of threats to its national security. But this is not our choice," the Russian statement said.
As part of the missile defense system, the United States plans to place interceptor missiles in Poland, but talks with Warsaw have stalled.
Russia has offered the U.S. the use of its radar stations in Armavir in southern Russia and Gabala in Azerbaijan as alternatives, but Washington said they could only be used as "supplements," if at all.
The ministry said all Russia's proposals aimed at reducing its concerns have been rejected. "The measures to provide transparency and control were rejected by the American party," it said in the statement. "So, a corresponding agreement between the Russian and U.S. presidents consolidated in a declaration in [Russia's resort of] Sochi on April 6, 2008, is undermined."
The statement said Moscow would be still open to constructive talks on the U.S. missile defense plans, but only on equal terms and "based on the need to maintain the required security of our country."