(Adds quotes, background) By Natalia Reiter WARSAW, Jan 22 (Reuters) - Placing a U.S. anti-missile system on Polish and Czech soil would strengthen Europe's defence against a rogue nuclear attack but would not threaten Russia, a senior U.S. official was quoted on Monday as saying. A top Russian general criticised Washington's plan but U.S. Assistant Secretary of State Daniel Fried told the Polish daily Rzeczpospolita that Moscow had nothing to fear. "We believe that building infrastructure of the anti-missile shield in Poland and the Czech (Republic) will significantly boost the defences of a united Europe," Fried said. "I want to stress that the anti-missile system is not aimed at Russia." The United States is investing billions of dollars a year in a Missile Defence Initiative (MDI) system, which would combine long-range radars and ballistic rockets to detect and shoot down missiles carrying nuclear, bacteriogical or chemical warheads. Fried said Washington had made a specific offer to Warsaw and Prague last week to start detailed negotiations, which he said could last for months, on hosting a part of the system. Under the proposal, Poland could be the base for underground rocket silos and the Czech Republic would host the radar system. The site would be the biggest element of the MDI shield outside the United States. U.S officials say the system will protect it and its allies from missiles that could be fired from North Korea, Iran or other "rogue regimes". Asked if Washington was speeding up talks on the system because of tensions with nuclear proliferators, Fried said: "I don't think we need to act under any time pressure. Polish concerns, the conditions for building the base and the basis for our cooperation must be carefully discussed." RUSSIA OPPOSED Poland, a close U.S. ally since overthrowing communism in 1989, has long been considered a potential location for rocket batteries. But Russia, Poland's former Warsaw Pact overlord, sees the shield as weakening its own security and has warned Warsaw it could take unspecified measures if it is built in Poland. "Our analysis shows that the placing of a radio locating station in the Czech Republic and anti-missile equipment in Poland is a real threat to us," Russian news agencies quoted space forces commander Lt.-Gen. Vladimir Popovkin as saying. Polish and U.S. diplomats say Russia's main concern is that the shield might weaken its nuclear deterrent and disturb the military balance in Europe. Poland's parliament would have to endorse a decision to host the missiles, amid some public scepticism about the project. Opposition to the plan has come also from within the ruling coalition, but some opposition parties are likely to back Prime Minister Jaroslaw Kaczynski, who supports it. Defence Minister Radoslaw Sikorski told Polish television on Sunday that safeguarding Poland's security would be the most important factor in the government's decision. "I think we want to assure the Polish public that we will approach this issue very seriously," he said.
