Poland's Prime Minister Donald Tusk (r) and U.S. Ambassador to Poland Victor Ashe, 03 Jul 2008

Polish officials are downplaying reports that they have reached agreement with the U.S. on plans to base part of an American missile shield in Poland.

U.S. officials said Wednesday they have reached a tentative deal on the plans. But Poland's defense minister, Bogdan Klich, said Thursday that negotiations were still ongoing, and that no firm agreement has been reached.

A Polish government spokesman issued a statement saying Prime Minister Donald Tusk and U.S. Vice President Dick Cheney discussed the state of negotiations for about 40 minutes by telephone Thursday evening. The spokesman did not reveal any details.

Any agreement on the missile shield still will need final approval from the Polish government in Warsaw.

The U.S. wants to base 10 interceptor missiles in Poland and a radar system in the Czech Republic, as part of a system to counter missile attacks from hostile states.

Russia has strongly opposed the plans as a threat to its security, although the United States says the system is intended for use against Iranian missiles, and not for use against Russia.

Some information for this report was provided by AFP and AP.