United Nations nuclear inspectors need to verify the plant is "fit for peaceful purposes," CNN quoted ElBaradei saying Sunday.
Iran acknowledged the plant's existence after western intelligence sources said they had been monitoring its development.
Iran maintains its uranium enrichment plants are designed to produce energy only, while the United States and other western countries have charged Iran with developing nuclear weapons.
The confusion can be resolved if Iran gives nuclear inspectors more information about declared nuclear activity and "possible undeclared activities," ElBaradei said.
Meanwhile, Iranian officials will meet Oct. 19 in Vienna with representatives from Russia, France and the United States on the country's request for enriched uranium to treat cancer patients, CNN reported.