Some countries, such as Turkey, have offered to mediate with the West to defuse mounting tension with Iran over the Islamic state's disputed nuclear activities, which the United States and its European allies fear is a cover for building bombs.
"We must be very naive to trust the West ... Why do they insist on swapping nuclear fuel abroad? It shows they have satanic intentions," Ali Akbar Velayati, Supreme Leader Ayatollah Ali Khamenei's top adviser on international affairs, told Iran's state news agency IRNA.
"Iran will never trust the West to send its Low-Enriched Uranium (LEU) abroad," he said.
Turkey has suggested itself as a third country where the uranium could be exchanged.
Asked whether such a swap could happen in Turkey - a NATO member which borders Iran and is also a temporary member of the UN Security Council - Velayati said: "The West can break its promises easily ... and Turkey cannot force them to fulfil their promises (to deliver nuclear fuel to Iran)."
Iran agreed to a Western offer last October to ship 1,200 kg (2,646 lb) of its LEU - enough for a single bomb if purified to a high enough level - to Russia and France to make into fuel for the Tehran Research Reactor.
Iran later said it would only swap its LEU for higher grade material and only inside its soil, conditions other parties in the deal said were unacceptable.
The United States is pushing UN Security Council members, to back a fourth round of international sanctions on Iran in the coming weeks, to pressure it to curb its nuclear activities. Iran says its nuclear program is aimed solely at generating electricity.
Iran's foreign minister and the UN atomic watchdog chief met on Sunday to discuss the stalled fuel deal. Sources in Vienna told Reuters that during the meeting Iran made another counter-offer to the deal.
The sources said Iran proposed an exchange on Iranian soil using a lower amount of LEU than in the International Atomic Energy Agency offer. Under Iran's new plan, this amount could be swapped simultaneously for half of the equivalent reactor fuel, with the rest of the fuel coming later.
Iran started enriching uranium to a higher level itself in February to create fuel for the research reactor. The move brings Iran's enrichment closer to levels needed for making weapons-grade material - uranium refined to 90 percent purity.
