These are two key steps the IAEA has said Iran must take before the UN nuclear watchdog meets November 20 to decide whether Iran is in compliance with the nuclear Non-Proliferation Treaty (NPT) and may be hiding an atomic weapons program.
"Next week we will get the letter by Iran for the conclusion of the additional (nuclear) protocol (on inspections), which is a positive step," IAEA director general Mohamed ElBaradei told reporters after meeting at his Vienna headquarters with Iranian security chief Hasan Rowhani.
"I was also told by Dr. Rowhani that next week we will get again a letter indicating Iran's agreement to suspend all (uranium) enrichment-related activities and reprocessing (of nuclear fuel) as a confidence-building measure, which is also a quite positive step," ElBaradei said after the meeting.
A ruling of non-compliance could lead to UN sanctions against Iran.
A Western diplomat told AFP the world was "still waiting for action that will demonstrate Iranian promises turning into reality because we've been disappointed in the past."
The United States accuses Iran, which is building a nuclear power reactor with Russian help, of secretly trying to develop nuclear weapons. Tehran vehemently denies the charge.
The IAEA had in September asked Iran to do three main things ahead of the November 20 board meeting -- fully disclose its nuclear program, agree to tougher inspections and suspend the enrichment of uranium that could be used to make the bomb.
Iran submitted on October 23 what it said was a full report on its nuclear program, eight days before a deadline for this set by the IAEA fell on October
Iran had on October 21 agreed, when the British, French and German foreign ministers visited Tehran, to suspend the enrichment of uranium, which produces fuel for reactors but also material that could be used to make the bomb.
The suspension has yet to come into effect and the Islamic republic has still to sign the additional NPT protocol, with next week's letter being a statement of intent and not the actual signing.
Rowhani said Iran would say next week exactly when the enrichment suspension would begin.
"I think we are moving together to try to resolve all remaining issues through cooperation and through verification," ElBaradei said.
Rowhani said he and ElBaradei had agreed that Iran's report had answered "all remaining questions" about its nuclear activities but ElBaradei stressed that while Iran has been given "satisfactory cooperation" the information has yet to be verified.
Rowhani said Iran has answered the IAEA's questions "pro-actively".
Rowhani made clear what Iran expects from its cooperation with the IAEA.
"We underline the fact that like any other signatory to the NPT, Iran should also be able to use peaceful nuclear technology," he said.
And he said that under the "new circumstances" of the increased cooperation, Iran should receive "technical assistance" in the form of peaceful nuclear technology transfers.
ElBaradei had said earlier this week that the IAEA will report that Iran has failed to honor some international nuclear safeguards.
Diplomats said however that it will take months to verify the information Iran has supplied and that this could be taken by the board as a reason not to pass judgement.
ElBaradei said: "We will need a few more months, particularly with regard to very complex investigations such as the source" of traces of highly enriched uranium found by IAEA inspectors in Iran.
Iran claims the uranium came from contamination of equipment it had bought abroad and not from producing the material, as the United States charges.