Czech Republic ? The United States has asked the Czech Republic to host a radar base that would be part of a global missile defense system, the prime minister announced Saturday, drawing a warning from Russia of retaliatory actions.

U.S. officials contend the system could defend Europe against intercontinental missiles fired by states such as Iran and North Korea. But the Kremlin warned that the military balance in Europe could be at stake and said the development risked a new arms race.

Independent defense experts have said the ground-based missile defense system is still years from being able to protect against long-range missile attacks.

Washington declined comment on Prime Minister Mirek Topolanek’s statement. But the U.S. has been negotiating with Poland and the Czech Republic, both former communist states now in NATO, as it explores setting up missile defense sites in Eastern Europe.

The U.S. has missile interceptor bases in Alaska and California. It activated a powerful X-band radar site in northern Japan as part of the system last September, but so far has no anti-missile weapons based outside U.S. territory.

The U.S. request that the Czech Republic host only an X-band radar facility could indicate Washington is considering putting launchers for anti-missile missiles in Poland.