WASHINGTON -- A U.S. congressional battle over funding of a U.S. missile-defense plan in Central Europe threatens to undermine the Bush administration's case that the system is not aimed at Russia.

President George W. Bush's administration has argued that the missile shield -- which was bolstered last week by the signing of an agreement to allow U.S. interceptors in Poland -- was aimed at securing the United States and allies from nuclear threats by North Korea and Iran.

But as Republicans try to convince Democrats to speed along legislation to fund the program, they are pointing to Russia's invasion of Georgia as a reason the program is vital. The rhetoric, however, risks strengthening Moscow's argument that the system, which Russia vociferously opposes, is merely a new Cold War incarnation directed against them.

"As Russian ballistic missiles rain down on Georgia, we should honor our commitment to allies in Poland and the Czech Republic," Republican Representative Mark Kirk said in a statement last week.

Kirk is seeking to boost funding for the plans to deploy 10 interceptors in Poland and a radar station in the Czech Republic. His amendment would restore funds cut from the Bush administration's request.

Congressional Democrats have sought to block funding for the construction of a base until Poland and the Czech Republic have given final approval -- their parliaments have not yet weighed in. In a separate bill nearing completion, they have restricted construction money until the new interceptors have been tested.

Democrats will not bend on the testing issue, said Democratic Representative Ellen Tauscher, one of the authors of the restrictions.

"The events in Georgia have nothing to do with the interceptors the U.S. is considering deploying in Poland, and Congress believes that this system is untested and fails to defend against current and emerging threats," she said in a written response to questions from The Associated Press. "Congress will not be funding an untested system, period."

The timing of the agreement in Poland has fueled Russian suspicions about the shield. After reaching an agreement with the Czech Republic in April, the Bush administration faced hurdles to deploying the system. But after Russian troops entered Georgia, Polish and U.S. negotiators quickly signed an agreement last Wednesday.

In signing the deal, Polish officials made clear they are more threatened by Russia than Iran and want a U.S. military presence on their soil. As part of the deal they got just that.

The United States now plans to deploy a Patriot anti-missile battery to Poland. The chief U.S. negotiator, acting Undersecretary of State John Rood, said a garrison with about 100 U.S. military personnel would be established by 2012.

Rood said Congress needed to take into consideration the security fears of Poland and the Czech Republic, now that agreements have been reached.

"I would be concerned about the signal it would send to our allies, should Congress not back the agreements," he said Monday. "We all have to consider very carefully how our actions are going to be read right now."