WARSAW, March 26 (Xinhua) -- The construction cost of a planned U.S. anti-missile shield in Poland and the Czech Republic is estimated at about 1.5 billion U.S. dollars, a top U.S. diplomat said Monday.

    "This is a very expensive system but the security of Europe and the U.S. is worth every penny spent on this goal," Deputy Chief of the U.S. Mission in Poland Kenneth Hillas told reporters in the Polish city of Cracow.

    Construction might start in mid-2008 if U.S.-Polish negotiations start as planned in a few weeks and end quickly with a positive outcome, the Polish PAP news agency quoted Hillas as saying.

    The shield could become operational in 2012 in that case, he said.

    Hillas said the shield was purely defensive and designed to defend nearly the entire Europe and the U.S. against intercontinental ballistic missiles from the Middle East, mainly Iran.

    But the system would not be able to intercept Russian ballistic missiles aimed at the U.S., of which the Russians were aware, he said.

    The U.S. in January proposed installing parts of its anti-missile shield in central Europe, including some interceptor missiles in Poland and a radar system in the Czech Republic.

    The move has drawn sharp criticism from Russia, which warned it could trigger arms race.

    The plan also prompted concern from U.S. allies such as Germany and France. Poland and the Czech Republic welcomed the U.S. missile plans, however.