Secretary of State Condoleezza Rice plans Wednesday to sign a deal to build a U.S. missile defense base on Polish soil, an agreement that has already prompted an infuriated Russia to threaten its former Soviet satellite.

The deal to install 10 U.S. interceptor missiles just 115 miles from Russia's westernmost frontier also has strained relations between Moscow and the West, ties that already troubled by Russia's invasion of its former Soviet neighbor, U.S. ally Georgia, earlier this month.

Rice flew to Poland Tuesday after meeting with NATO foreign ministers in Brussels, Belgium, where the military allies agreed to suspend formal contacts with Russia as punishment for the Georgia conflict, but resisted U.S. pressure for more severe penalties.

The U.S. says the missile defense system is aimed at protecting the U.S. and Europe from future attacks from states like Iran. Moscow insists that it is a threat to Russia.

After Warsaw and Washington announced the agreement on the deal last week, top Russian Gen. Anatoly Nogovitsyn warned that Poland is risking attack, and possibly a nuclear one, by deploying the American missile defense system, Russia's Interfax news agency reported.

Poles have been shaken by the threats, but NATO Secretary General Jaap de Hoop dismissed them Tuesday as "pathetic rhetoric."

"It is unhelpful and it leads nowhere," he told reporters at the NATO meeting.

Many Poles consider the agreement a form of protection at a time when Russia's actions in Georgia have generated alarm throughout Eastern Europe. Poland is a member of the European Union and NATO, and the deal is expected to deepen its military partnership with Washington.

Polish President Lech Kaczynski said Wednesday will be "an important day in our history."

He stressed that the missile defense shield was purely a defensive system and not a threat.

"For that reason, no one who has good intentions toward us and toward the Western world should be afraid of it," he said.

Poland and the United States spent a year and a half negotiating, and talks recently had snagged on Poland's demands that the U.S. bolster Polish security with Patriot missiles in exchange for hosting the missile defense base.

Washington agreed to do so last week, as Poland invoked the Georgia conflict to strengthen its case.

The Patriots are meant to protect Poland from short-range missiles from neighbors _ such as Russia.

The U.S. already has reached an agreement with the government in Prague to place the second component of the missile defense shield _ a radar tracking system _ in the Czech Republic, Poland's southwestern neighbor and another formerly communist country.

Approval is still needed the Czech and Polish parliaments.

No date has been set for the Polish parliament to consider the agreement, but it should face no difficulties in Warsaw, where it enjoys the support of the largest opposition party as well as the government.