Istanbul, Turkey ? The Bush administration is exploring the possibility of expanding the nascent U.S. missile defense system into Eastern Europe as a protection against an attack from the Middle East.

U.S. diplomats and Defense Department officials have been quietly talking with NATO members Hungary, Poland and the Czech Republic about whether one of them might host the new launch site, U.S., Hungarian and Czech officials told Knight Ridder.

The facility would comprise underground silos housing interceptor-tipped missiles that would be fired at enemy missiles as they soared through space. A network of powerful radars would guide the interceptors into collisions with their targets.

A launch site in any of the three former Soviet-bloc nations would be able to defend the United States and its European allies from attacks by missiles fired from the Middle East.

Iran — whose hard-line Islamic regime is part of what President Bush called “the axis of evil” — is believed to be developing nuclear weapons and long-range missiles that might pose such threats in the future, U.S. officials said.