TEHRAN, March 6 (RIA Novosti) - Iran will conduct air defense exercises Tuesday in preparation for a possible air strike on its uranium ore conversion center at Isfahan, the IRNA news agency said Tuesday.

The international press has in recent months actively discussed the possibility of U.S. and Israeli air strikes on Iranian nuclear facilities, but almost all key figures in the Bush administration have repeatedly refuted the existence of any plans to do so.

However, U.S. Vice President Richard Cheney has not ruled out a military strike, saying all options were on the table.

The International Atomic Energy Agency (IAEA) Board of Governors convened Monday at its Vienna headquarters for a five-day session to discuss the possible suspension of at least 20 aid projects in Iran following a recent report by IAEA Director General Mohamed ElBaradei, which concluded that Iran has ignored a UN Security Council demand to halt its uranium enrichment program and was in fact seeking to expand it.

Iran has been at the center of international concerns since January 2006 over its nuclear program, which some countries, particularly the United States, suspect is geared toward nuclear weapons development. Tehran has consistently denied the claims, saying it needs nuclear power for civilian purposes.

In response to Iran's unwillingness to give up its nuclear ambitions, the UN Security Council adopted Resolution 1737 last December, which provided for sanctions against Iran banning activities involving uranium enrichment, chemical reprocessing, heavy water-based projects, and the production of nuclear weapons delivery systems.

The nuclear center dealing with uranium ore conversion in Isfahan has an area of 120,000 square meters (360,000 square feet). Uranium ore is processed into a gaseous hexafluoride of uranium, which is then fed into a centrifuge cascade for enrichment.

Uranium enrichment using centrifuges is conducted at a plant in Natanz.

Ali Larijani, the secretary of Iran's Supreme National Security Council, said Tuesday that any military strike against Iran would be ineffective.

"Any military actions against Iran will not only be ineffective, but would make the Iranian nation even more resolute," he said.

Larijani said the Iranian nuclear issue could only be resolved through talks.

Russia's Foreign Ministry said Tuesday that Foreign Minister Sergei Lavrov and U.S. Secretary of State Condoleezza Rice have discussed the situation surrounding the Iranian nuclear program by telephone.