MOSCOW, Feb. 20 -- An increasingly angry dispute over U.S. plans to deploy a missile defense system in Central Europe is adding strain to already fragile U.S.-Russian relations.

Under the proposal, the United States would build silos in Poland to hold 10 interceptor rockets that could destroy intercontinental ballistic missiles fired at the United States or even command sites in Europe. The accompanying radar system would be located in the Czech Republic.

U.S. officials say the system is not directed against Russia, but at the potential threat posed by missiles being developed by Iran.

That argument has been dismissed in Russia as spurious. Senior military officials, who have begun to drive the debate here, have responded with rhetoric rarely heard since the end of the Cold War.

"If the governments of Poland and the Czech Republic take such a step, the strategic missile forces will be capable of targeting these facilities if a relevant decision is made," Gen. Nikolai Solovtsov, commander of Russian missile forces, said at a news conference Monday.

Polish Prime Minister Jaroslaw Kaczynski said Tuesday that Solovtsov's statement "was obviously an attempt at intimidation."

"To make it clear, this is not about Russian security; these installations do not in any way threaten Russia," Kaczynski said on Polish radio. "We are talking about the status of Poland and Russia's hopes that Poland will once again come under its sphere of influence."

Czech Foreign Minister Karel Schwarzenberg told the Reuters news agency in Warsaw that his nation would not give in to Russian "blackmail."

Relations between the United States and Russia had already taken a hit this month when Russian President Vladimir Putin lashed out at Washington for its unilateral approach. "The United States has overstepped its national borders in every way," Putin said. He also said U.S. plans for an antimissile system could upset the international balance of power. His remarks drew rebukes from the White House.

Russian officials have said that Iran has no missiles capable of reaching the United States or even Western Europe and that Iran is incapable of developing them any time soon. Sergei Ivanov, then defense minister, told the German newspaper Die Welt this month that it would take "at least 20 years" for Iran to develop missiles that could reach Central Europe.

"I think you can draw your own conclusions about which missiles this system actually targets," Solovtsov said. "This is why we are watching the situation with anxiety and concern."

Solovtsov said it would take Russia less than six years to build and deploy upgraded missiles to counter what it sees as a threat. And Putin warned this month that "we need to respond asymmetrically, so that everyone understands that yes, there is an antimissile system, but it's useless against Russia."

If the United States goes ahead with its plans, Russian officials have threatened to pull out of the 1987 Intermediate-Range Nuclear Forces Treaty, which eliminated shorter-range missiles. As precedent, Russian officials cite the Bush administration's withdrawal from the 1972 Anti-Ballistic Missile Treaty.

"It is possible for a party to abandon the treaty if it provides convincing evidence that it is necessary to do so," Gen. Yury Baluyevsky said this month. "We have such evidence at present."

Irina Kobrinskaya, an analyst at the Institute of World Economy and International Relations in Moscow, said the Russian military might have grudgingly accepted the system if it were deployed on NATO's southern rim in Turkey, Romania or Bulgaria. But its placement to the north -- in the Czech Republic and Poland, which shares a land border with the Russian region of Kaliningrad -- has raised deep suspicion here.

"Elements of this new system can present a threat to Russia and that's the logic of the military," Kobrinskaya said in an interview.

For Russians, the system is part of a deeper pattern of what they see as U.S. encirclement, particularly through the continuing expansion of NATO. From its first expansion into the former Soviet bloc in 1998, when Poland, Hungary and the Czech Republic joined, NATO now includes the three Baltic states, Slovakia, Romania and Bulgaria. The former Soviet republic of Georgia also wishes to join. Some politicians in Ukraine, including President Viktor Yushchenko, have advocated membership.

Some Russian analysts contend that part of the rhetoric is driven by domestic political concerns and efforts to build a nationalist consensus before parliamentary and presidential elections.

"I think the whole episode is being used by the Russian government to substantiate its critical approach to what the U.S. is doing internationally," said Viktor Kremenyuk, of Institute of the United States and Canada in Moscow, in an interview.

U.S. officials have said they accept that Russia could easily overwhelm the antimissile system -- further proof, they say, that it is not directed against Russia.

U.S. Air Force Lt. Gen. Henry Obering, head of the Missile Defense Agency, told reporters last month that the interceptors "are directed toward rogue nations' capabilities, not an obviously sophisticated ballistic missile fleet such as the Russians have."