"Unfortunately, the export of nuclear fuel in the world has turned from a trade and economic matter into a political problem, and there is no such thing as guaranteed nuclear fuel supplies," Mohammad Saidi said.
He added that the idea of establishing an international uranium enrichment center in Iran, proposed by President Mahmoud Ahmadinejad in 2005, still stands.
The official said the center would be open to foreign states and private companies. And stressed that despite international pressure on Tehran, it will continue its nuclear program.
Russia previously proposed the creation of international enrichment centers on its soil, but Tehran rejected the idea, insisting on its right to pursue an independent program.
"Some countries have acknowledged our achievements in the nuclear sphere and some have not. Those who have not, will be forced to do so eventually," Saidi said.
Iran said earlier it had started tests of advanced uranium enrichment centrifuges.
Ahmadinejad announced tests on advanced nuclear equipment on Tuesday - Nuclear Technology Day in Iran - also adding that the country had started to install another 6,000 'ordinary' uranium enrichment centrifuges at its underground facility in Natanz.
Iran currently uses around 3,000 'P-1' centrifuges, according to the UN nuclear watchdog, the IAEA, that are prone to breakdown when working at high speed for long periods.
The announcements apparently signal that Iran has no interest in taking steps to avoid a third set of UN Security Council sanctions over its defiance to halt uranium enrichment, used both in weapons and electricity production. A resolution on a third set of sanctions was adopted in late February and will come into force when a 90-day deadline expires.
Tehran has repeatedly rejected international demands to halt uranium enrichment, insisting it needs the process to generate electricity.
Another Iranian nuclear official announced on Wednesday that the country was planning to build another uranium processing plant by next March.
"A second plant will be launched in the city of Ardakan, in the Yazd Province," Hossein Fagihian from the Atomic Energy Organization of Iran said.
He said the plant would fully meet Iran's need for yellowcake, a uranium concentrate which is an intermediate step in the processing of uranium ores.
The country's nuclear ambitions have contributed to tensions with Washington, with U.S. President George Bush refusing late last year to rule out military action against Tehran.
However, Russian Foreign Minister Sergei Lavrov said on Tuesday that the six countries mediating in the nuclear dispute with Iran - the five permanent UN Security Council members and Germany - were preparing new incentives to convince Tehran to halt its uranium program.
Deputy foreign ministers of the Iran Six will gather in Shanghai on April 16 to discuss plans to resume nuclear talks with the Islamic Republic.
