Defense Secretary Donald Rumsfeld appeared to signal Wednesday that the United States has no objections if Russia pursues an expanded missile defense system with space-based components.
Mr. Rumsfeld appeared untroubled by Russian Defense Minister Sergei Ivanov's statement that Moscow intends to develop a missile defense shield similar to the one planned by the United States.
The U.S. defense secretary, responding to a reporter's questions, noted Wednesday that Moscow has long had nuclear-tipped missile defenses around Moscow.
He said any expansion of those defenses would clearly reflect Russia's shared concern about the growing threat posed by the proliferation, not only of long-range missiles but also weapons of mass destruction.
"The Russians look at the world, just like we do, and they see countries that are developing longer-range ballistic missiles," he said. "They see the proliferation of chemical and biological and nuclear capabilities to countries that it is extremely worrisome that they have them."
Russia has in the past voiced concern about the possible destabilizing effects of the U.S. missile defense program.
But General Richard Myers, chairman of the Joints Chiefs of Staff of the U.S. military, noted at the Pentagon Wednesday that the United States has offered to work with Russia on the technical aspects of missile defense.
General Myers also said the United States and Russia have held at least two joint missile defense exercises in recent years and a third is now in the planning stages.
The military's missile defense organization says the two countries conducted what are termed command post missile defense exercises in 1996 in Colorado and in 1998 in Moscow.
In his remarks Wednesday at a missile base outside Moscow, Russian Defense Minister Ivanov said the U.S. withdrawal from the 1972 Anti-Ballistic Missile treaty had freed Russia from the restrictions of the pact.
But he noted the expansion of Russia's missile defense program would in part be dependent on the state of the country's economy.