Iran began enriching uranium to a higher level on Tuesday, an acceleration of its nuclear program that was followed by a US threat of a "significant regime of sanctions."
Ali Akbar Salehi, a vice president as well as the head of the country's nuclear program, said the further enrichment would be unnecessary if the West found a way to provide Iran with the needed fuel.
"Whenever they provide the fuel, we will halt production of 20 percent," he told state TV late Monday.
Speaking in Washington, US President Barack Obama said the process ofdeveloping an additional set of sanctions on Iran was moving alongquickly, but he gave no specific timeline.
Iran has so far enriched uranium to a level of 3.5 percent, which is suitable for use in fueling nuclear power plants.