TEHRAN (AFP) - Iranian Foreign Minister Manouchehr Mottaki on Tuesday accused the United States of abducting its nuclear scientist Shahram Amiri who went missing in Saudi Arabia earlier this year. Based on existing pieces of evidence that we have at our disposal the Americans had a role in Amiris abduction, Mottaki said at a Press conference in Farsi which was translated into English by Press TV channel. The Americans did abduct him. Therefore, we expect the American government to return him. Mottaki said Amiri had travelled to Saudi Arabia to perform Haj when he disappeared. He disappeared in Saudi Arabia and naturally we ask the Saudi government to look into the case.... Saudi Arabia must be held accountable in this regard. Earlier Tuesday, Iranian Foreign Ministry spokesman Ramin Mehmanparast claimed that Riyadh had handed Amiri over to Washington. Talking to Mehr news agency, Mehmanparast also acknowledged that Amiri was a nuclear scientist, something which Iranian officials had previously evaded to reveal, adding that the scientist is one of the 11 Iranians being held in US jails. Irans nuclear scientist who had gone to Haj in Saudi Arabia, was handed over by Riyadh to Washington, he said. Iranian media have also previously reported that US Central Intelligence Agency of being involved in his disappearance. Amiri left for Saudi Arabia on May 31 and on his arrival was questioned by Saudi agents at the airport for a longer time than other pilgrims, Irans Javan newspaper said in October. Three days later when he left his hotel in Madina, he never returned, the report said, adding that Amiri was a researcher at Tehrans Malek-Ashtar University of Technology. The newspaper quoted his wife as saying he was only a researcher and did not hold any government post. Mehmanparast, meanwhile, told a media conference earlier Tuesday that Iran has no faith in world powers when it comes to resolving a dispute over a nuclear fuel deal. We never said we will not do this (nuclear fuel deal), Mehmanparast said when asked if Iran was still weighing up whether to subscribe to the deal brokered by the International Atomic Energy Agency (IAEA). The question is the attitude of some Western countries in the past. They have lost trust and have never kept their promises, he said. He also implicitly rejected Turkeys desire to mediate between it and world powers. Turkish Prime Minister Recep Tayyip Erdogan criticised the West for being too quick to censure Irans nuclear program, and told President Barack Obama during his visit in Washington that Ankara is prepared to mediate with Tehran. Obama, who welcomed Erdogan Monday to the White House, said Turkey could be an important player in trying to move Iran towards abiding by international norms and atomic rules. He said solving the controversy over Tehrans nuclear drive does not need additional parties. Turkey wants to play a role in solving the nuclear issue between the countries who have the technology and the countries who are seeking it, he said. But we dont think that our views are non-transparent and they needed to be interpreted by others. All our nuclear work is under the supervision of the agency and we have informed it of our future plans. Mehmanparast also dismissed Western threats to impose a fourth set of UN sanctions on Tehran if it does not come clean on its nuclear programme. If there is another round of sanctions we will be more serious in pursuing nuclear technology.