The confidential report by IAEA Director-General Mohamed ElBaradei, a copy of which was obtained by the BBC, said Iran had made progress in responding to questions about its past nuclear activities.
"Iran has provided sufficient access to individuals and has responded in a timely manner to questions and provided clarifications and amplifications on issues raised in the context of the work plan," the report said.
But a new IAEA report also said Iran had not suspended uranium enrichment work as demanded by the UN Security Council and had 3,000 centrifuges.