Iran's foreign ministry is pledging to answer all questions that the United Nations nuclear agency still has about its past nuclear activities.
Following a two-day visit by International Atomic Energy Agency chief Mohammed ElBaradei to Tehran, a foreign ministry spokesman said officials have agreed to clear up remaining questions in the next four weeks.
Iran also said it gave ElBaradei information about a new generation of uranium-enrichment centrifuges that Iranian nuclear scientists are developing.
Iran's Supreme Leader Ayatollah Ali Khamenei told ElBaradei Saturday that the IAEA, not the U.N. Security Council, should be the institution in contact with Iran about its nuclear program.
The Security Council has imposed two rounds of sanctions on Iran for its failure to suspend uranium enrichment, a process that can be used in making nuclear weapons.
The United States and other western countries believe Iran is developing nuclear technology to produce nuclear weapons - a charge Iran has denied.
Iran insists its nuclear program is peaceful and it has the right to enrich uranium.
Some information for this report was provided by AFP, AP and Reuters.