WARSAW, April 24 (Xinhua) -- U.S. Defense Secretary Robert Gates said here on Tuesday it was up to NATO to decide whether Poland can receive a Patriot air defense system as an extra safeguard in connection with the location of a U.S. anti-missile shield on its territory.

    Gates started Tuesday a two-day visit to Poland. Earlier he met with Polish Defense Minister Aleksander Szczyglo.

    Gates noted the shield was designed against threats expected in10-20 years, not now.

    "We have agreed that the project of an anti-missile shield should increase security in Europe and Poland," the Polish PAP news agency quoted Szczyglo as saying.

    According to Szczyglo, Russia's protests against the U.S. shield's location in Europe hang together with the country's internal situation and approaching elections.

    The United States 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 base in central Europe would supplement two others located in Alaska and California.