"We are making good progress in resolving the remaining outstanding issues of the past," said Mohammed ElBaradei, the head of the International Atomic Energy Association.
Iranian officials said they disclosed to ElBaradei information on a "new generation" of centrifuges used to refine uranium more quickly than their predecessors during his mid-January visit to Tehran.
ElBaradei said his final report on the Iranian nuclear program will provide information on the development of centrifuges and enrichment activity at the Natanz nuclear facility, the FARS news agency reported Monday.
The nuclear chief side stepped questions about the impact his report would have on additional U.S.-backed sanctions imposed on Iran.
"The agency can carry out inspections and give guarantees about the past and the present, but we cannot read future intentions," he said.