NATO defense ministers have ordered feasibility studies on a short-range missile defense system that would protect southeastern European nations left exposed by a proposed U.S. anti-missile shield elsewhere on the continent.
A final decision on building the NATO system is expected at an alliance summit next April in Romania.
Thursday's NATO talks in Brussels mark the first time the 26-nation military alliance has formally discussed the missile shield, which is opposed by Russia.
Under the proposal, the United States would deploy 10 missile interceptors in Poland and guidance radar in the Czech Republic. The study of an expanded system was ordered after complaints that four NATO countries - Bulgaria, Romania, Greece and Turkey - were only partly covered or left out of the U.S. plan.
U.S. and NATO officials are also studying a Russian proposal for a joint Russian-U.S. radar base in Azerbaijan.
NATO ministers also discussed the shield proposal Thursday with Russia's new Defense Minister Anatoly Serdyukov.
Separately, the NATO-Ukraine Commission met to discuss security reforms in Ukraine, and that country's participation in NATO-led military maneuvers.
Last month, Russian President Vladimir Putin threatened to point Russian missiles at Western Europe, if the alliance adopts the U.S. missile shield plan. He later offered the joint Azerbaijan base proposal as an acceptable alternative to the U.S. plan.
Moscow has argued the U.S.-built missile defense system would destabilize Europe and lead to a new arms race.
Washington insists Russia has nothing to fear from the system, which authorities say is aimed at defending against attacks from states such as Iran and North Korea.
Some information for this report was provided by AFP, AP and Reuters.