Washington is pushing for a European missile shield on the premise it would be a deterrent to a threat from Iran. That threat was renewed by an assessment from the International Atomic Energy Agency that Iran was working on some elements of a nuclear weapon.
Russian President Dmitry Medvedev said Moscow would respond in kind should the United States place a missile shield in his country's backyard.
"Russia will deploy in the west and the south of the country advanced offensive weapons systems which will target the European component of the (U.S.) missile defense network," he was quoted by state-run news agency RIA Novosti as saying.
Medvedev this week said a 2008 war with the former Soviet republic of Georgia stopped NATO's expansion eastward.
Moscow in August 2010 deployed its S-300 missile shield to Georgia's breakaway republic of Abkhazia to protect the airspace from "intruders."
Moscow recognized Georgia's breakaway republics shortly after the 2008 conflict and signed agreements in 2010 to build permanent military installations in the breakaway regions.
Washington considers Abkhazia part of Georgian territory but brushed off the concerns noting missile shields have been in place there for more than two years.