Russia opposes U.S. plans to base interceptor missiles in Poland and radar in the Czech Republic. The United States says that the shield is needed to protect Europe from strikes by "rogue states," presumably North Korea and Iran.

Lavrov said that U.S. proposals to deal with Russian opposition have not changed since Defense Secretary Robert Gates and Secretary of State Condoleezza Rice visited Moscow in March, the Novosti news agency reported. At that time, they offered to allow Russia to monitor the installations and said they would not be armed until there was a definite threat.

"Dialogue has stalled," Lavrov said.

Polish officials have said that the United States is also having discussions with Lithuania about basing the interceptor missiles in the Baltic States if talks with Poland break down. Lavrov said that Russia has received no official confirmation of that possibility.