The deal to place 10 interceptor missiles in Poland was reached last Thursday, and followed the signing of an agreement on July 8 by the U.S. and Czech foreign ministries to station a U.S. radar in the Czech Republic.
"This is an agreement that will establish a missile defense site here in Poland that will help us to deal with the new threats of the 21st century, of long range missiles ... from countries like Iran or North Korea," Rice told reporters.
Moscow has consistently expressed its opposition to the U.S. missile shield, saying it threatens its national security. The United States says the shield is designed to thwart missile attacks by what it calls "rogue states," including Iran.
However, Russian President Dmitry Medvedev said again last week that Moscow has no doubt the missile shield is aimed against Russia.
