Iran said Friday it was ready for immediate talks with the United States, Russia and France over an exchange of nuclear fuel and added that it was also against stockpiling higher enriched uranium. The comments by the country's atomic chief Ali Akbar Salehi came as Washington decided to fan out envoys across Asia, Middle East and the United Arab Emirates asking its partners to levy tighter sanctions against Tehran. “We are ready even in the next few days to start negotiations with the other parties” over the fuel swap, Salehi was quoted as saying by Mehr news agency. He said talks on this issue with the so-called Vienna group comprising the United States, Russia and France will be held in Vienna, where the UN atomic watchdog the International Atomic Energy Agency (IAEA) is based. The Vienna group has raised questions about a proposal forwarded by Iran, Brazil and Turkey concerning a fuel swap. The May 17 proposal, known as the Tehran Declaration, stipulates that Tehran send 1,200 kilograms of its low-enriched uranium (LEU) to Turkey in return for 20 percent high-enriched uranium to be supplied at a later date. The enriched uranium, when converted into fuel plates, will be used for a Tehran-based research reactor. Salehi said Iran has already responded to the questions raised by the Vienna group, but that any other “technical” queries can be answered during another meeting. On Friday, Salehi again attempted to clarify Iran's position, saying that it was against stockpiling the 20 percent enriched uranium. “We need 20 percent fuel for the Tehran research reactor at the moment,” Salehi said. “We have said before that we are producing 20 percent only for our needs. We do not want to stockpile 20 percent fuel.” Salehi, meanwhile, indicated that the overall nuclear talks between Iran and the six world powers – Britain, China, France, Russia, the United States and Germany – could be held in Turkey at the the end of Ramadan, in mid-September. “As I know, Iran prefers to organize these talks in Turkey,” he told ISNA news agency. Iran's arch-foe the United States announced Thursday that top officials will visit China, the United Arab Emirates and other key countries in support of tighter sanctions against Tehran. “China is of concern to us in this regard,” Robert Einhorn, the US State Department's special adviser for non-proliferation and arms control, told the House Oversight and Government Reform Committee.