According to the official IRNA news agency, Elham said Iran has also achieved progress in other areas of science and technology.

The Iranian government spokesman made the remarks in a pre-sermon lecture at the Friday prayer congregation in Tehran, but he did not elaborate on when Iran would make the announcement.

On Wednesday, the semi-official Mehr news agency said that Iran would soon announce an atomic breakthrough, which came just one day after Tehran made a response to a six-nations package aimed at resolving the Iranian nuclear issue.

"This great scientific achievement is the result of a long-term research project ... A top official will formally make the announcement," Mehr quoted an unidentified source as reporting.

"The announcement will highlight Iran's mastery of different areas in nuclear science and will reinforce Iran's position as a nuclear country," the report said.

Iran is accused by the West of trying to produce nuclear weapons under the cover of a civilian nuclear power program.

However, Iran, the world's fourth largest oil exporter, says it needs to enrich uranium as a peaceful, alternative energy source and has the right to do so under the nuclear Non-Proliferation Treaty.

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 also can be used for building nuclear weapons at a degree of enrichment as high as 90 percent.

On June 6, EU foreign policy chief Javier Solana presented Iran with a package agreed on by the five permanent members of the UN Security Council, namely the United States, Russia, China, France and Britain, plus Germany concerning the Iranian nuclear issue.

The proposal includes both incentives aimed at persuading Iran to suspend uranium enrichment and possible sanctions if Iran does not comply.

Iran's top nuclear negotiator Ali Larijani delivered Teheran's written response to the incentives package on Tuesday and urged the six nations to get back to negotiations, saying Iran was ready to start "serious talks" over its nuclear program.

The United States said on Wednesday that Iran's response fell short of the conditions of a UN Security Council resolution.

"The response however, falls short of the conditions set by the Security Council, which require the full and verifiable suspension of all enrichment-related and reprocessing activities," U.S. State Department spokesman Gonzalo Gallegos said in a statement.

The UN Security Council on July 31 adopted a resolution urging Tehran to "suspend all enrichment-related and reprocessing activities, including research and development" by Aug. 31 or face the prospect of sanctions.

Iran has rejected the resolution, saying it has no legal basis.