"We don't have to have this installation on our territory if it doesn't clearly serve to increase our security," Koziej added.

The Pentagon said in May that the United States is consulting European allies about deploying missile defenses in Europe to thwart a Middle Eastern ballistic missile threat.

The New York Times said the US administration's proposal calls for installing 10 missile interceptors at a European site by 2011, at an estimated cost of 1.6 billion dollars, to protect Europe and the United States against missile attacks by Iran.

The paper said a recommendation on a European site is expected to be made this summer.

Pentagon spokesman Bryan Whitman said last month that no decisions have been made but acknowledged consultations were under way with interested European allies, including Poland.

Koziej said Poland was waiting for a concrete offer from the United States that will take into account the central European country's needs and national interests.

"For the moment Poland is not committing itself," he added. "No final decision has been made."

A senior US defence official told AFP last year the European site could be very similar to the US site in Fort Greely, Alaska where half a dozen ground-based missiles are positioned to intercept potential long-range missile attacks from North Korea.

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