All sides agreed to continue talking for four more months to try reach a final agreement.
Six world powers are negotiating with Iran to scale back on enrichment capacity sharply.
The IAEA said more work was still needed for the implementation of a series of nuclear transparency steps.
World powers start talks with Iran next week on a final agreement expected on the issue.
There's been a potential breakthrough in the investigation into Tehran’s atomic activities.
Iran’s Foreign Minister is not concerned about the US Congress trying to impose new sanctions.