The Iranian Student's News Agency (ISNA) earlier quoted Mohammad Saeedi, deputy chief of Iran's atomic energy agency, as saying that it would not be surprising if Iran enriched uranium to 20 percent, which was required for its new light water nuclear reactor project.

But an Iranian nuclear official, who speak on condition of anonymity, later denied the report, saying Iran has no plan to build light water nuclear research reactors.

In April, Iran declared that it had gained a ticket to join the global nuclear club by having successfully produced 3.5 percent enriched uranium, a technological leap in the process for nuclear power plant construction.

Enriched uranium is the key material for civil nuclear fuel cycle construction, but it can be used for building nuclear weapons at a degree of enrichment as high as 90 percent.