Russia's envoy to NATO today called for guarantees from Washington that a revised U.S. missile defense plan won't threaten Moscow, according to AP. Dmitry Rogozin said the prospective U.S. system _ involving missiles on navy ships _ could potentially cause Russia concern. He said Moscow wants assurances that the system would only be aimed to counter short- and medium-range missiles, and would not be moved near Russian borders or compromise Russia's own strike capability. «If this system goes mobile, then where are the guarantees that this mobile thing, be it a boat, a cruiser, or a battleship ... will not sail into our northern seas?» Rogozin said at a news conference. President Barack Obama this month dumped a plan for 10 interceptor missiles in Poland and a related radar in the Czech Republic, which Moscow fervently opposed. Obama said a missile shield involving a network of sensors and missiles at sea or on land would be deployed instead. The missile defense issue has been a thorn in Washington-Moscow relations, and the Kremlin has cautiously welcomed Obama's move.