The Russian leader has said there must be concessions from America on its planned missile defence shield in eastern Europe, if the two superpowers are to come to a deal on cutting strategic nuclear warheads. Dmitry Medvedev was speaking on the eve of negotiations with Barack Obama to replace the 1991 Strategic Arms Reduction treaty.He said: “We are not agaist the developing of such defence systems but we believe that they must not be “one-sided”, that is turned against one of the partners participating in the dialogue, against large nuclear powers such as Russia. (This system) must be a measure of global defence, turned against those countries which pose a threat today.” America wants to build a missile shield in Poland and the Czech Republic, to protect against what it calls “rogue states” like North Korea and Iran. But Russia has felt threatened. Obama is due in Moscow on Monday to explore ways of replacing the START treaty which expires in December. The US President said America respects Russia and he wants to deal with Moscow as an equal. He said his goal is for both countries to reduce nuclear stockpiles in a way that neither has an advantage over the other.