Iran has signed an agreement brokered by Brazil to ship low-enriched uranium to Turkey in exchange for nuclear fuel for its power plant, according to official media. Mahmoud Ahmadinejad, the Iranian president, signed the deal on Monday following a breakfast with his Brazilian counterpart and the Turkish prime minister. The move aims to ease Western concerns over Iran's nuclear programme, and stave off a possible new round of sanctions by the United Nations. Reports said Iran had agreed to swap 1,200kg of uranium for the higher-enriched nuclear fuel, which would be used in a medical research reactor. Manouchehr Mottaki, the Iranian foreign minister, said in the event the deal is not implemented, Iran's uranium must be returned. "Based on the agreement signed this morning, if the swap does not take place, then Turkey will be obliged to send back our dispatched uranium immediately and unconditionally," Mottaki said.