BUDAPEST --- The United States and the Czech Republic have signed an agreement that will allow construction of part of a missile defense shield. The document was signed by U.S. Secretary of State Condoleezza Rice and her Czech counterpart, despite mounting opposition against the project.>> Secretary of State Condoleezza Rice and Czech Foreign Minister Karel Schwarzenberg signed a deal to build a radar station southwest of Prague, which will be part of a missile-defense system the United States says is aimed at shooting down missiles that may be fired from Iran or North Korea.>> Besides the tracking radar system in the Czech Republic, the United States plans to deploy 10 interceptor missiles in Poland. Washington wants the sites to be in operation by 2012.>> Talks are reportedly also under way to station up to 250 American troops in the Czech military base in Brdy, to service the radar station.>> But the agreement faces major political hurdles. The accord has to be ratified by a divided Czech parliament where the government has just half the chamber's 200 seats.>> In addition, opinion polls show two-thirds of Czechs opposing the project and there have been demonstrations and hunger strikes against the plan.>> Analysts say there is general mistrust towards foreign powers in the Czech Republic, which this year commemorates the 40th anniversary of the invasion by the Soviet Union that crushed a period of political and economic reforms, known as the Prague Spring.>> Another concern is Russia's opposition towards the missile-defense system, saying it would pose a threat to its own security. Moscow has threatened to aim its own, potentially nuclear, missiles at any eventual base in the Czech Republic or Poland.