Iranian and European diplomats will hold talks Monday on possible incentives to ensure Tehran does not develop nuclear weapons.
Iran's top nuclear official (Hassan Rohani) will meet in Brussels with diplomats from France, Britain and Germany.
Last month, Iran agreed to a European-brokered deal to temporarily suspend uranium enrichment activities. The accord staved off a U.S. push to bring the matter to the U.N. Security Council for possible sanctions.
Washington alleges Iran is secretly trying to develop nuclear weapons, a charge Tehran denies.
The head of the International Atomic Energy Agency, Mohamed ElBaradei, has told Iran that suspending enrichment activities would build international confidence.
Iran has said it will never agree to permanently freeze uranium enrichment--a process that can be used to make energy or weapons.