The U.S. remains committed to all four phases of the European Phased Adaptive Approach to missile defense, despite Russia’s strong objections, according to Ellen Tauscher, U.S. special envoy for Strategic Stability and Missile Defense.

Tauscher and Madelyn Creedon, assistant secretary of Defense for Global Strategic Affairs, told reporters in a teleconference this week that while the Obama administration welcomed the opportunity to participate in Moscow’s recent missile defense conference, U.S. policy remains firm on the Lockheed Martin Aegis-based approach to NATO missile defense.

“There’s no indication that we might give up the interceptors in Poland,” Creedon says. “We’re not agreeing to any limitations on our systems.” Moscow has vociferously opposed any strategic Western missile defense system, including the final phases of the EPAA, and continues to warn about nuclear weapons deployments and projects it will undertake if Washington does not heed its desire for a legally binding guarantee against aiming the shield at Russia.

“While we can work cooperatively together, we cannot agree to pre-conditions outlined by the Russian government,” Tauscher reiterates. The White House is willing to offer a non-binding political statement of intent over its missile-defense system and continues to see areas of potential partnership, such as Russia’s radars.