The International Atomic Energy Agency says it expects a whole range of detailed documents related to Iran's past nuclear program to be submitted Thursday.
The Vienna-based U.N. nuclear watchdog agency expects documents on Iran's nuclear activities and a letter of intent allowing for broader inspections to arrive Thursday.
The IAEA board of governors has given Tehran until the end of October to make a complete and accurate declaration of its nuclear activities to prove that its program is purely peaceful.
IAEA spokeswoman Melissa Fleming says Tehran needs to answer important questions, such as "What kind of work have you done on your laser program? What have you done on your heavy water program? We have got lots of information and we have got a lot of knowledge and we have got a lot of indicators and the question is whether when they tell the full story with this full declaration will this fill in all the holes," the spokeswoman said.
Ms. Fleming says the agency will start comparing the Iranian file with its own notes right away.
Tehran has also promised to send the agency an official letter confirming that it will sign a so-called additional protocol giving international inspectors greater rights of access to locations in Iran.
But Ms. Fleming says it would be wrong to talk of unlimited inspections. "It is not like Iraq - unfettered access any time, any place," she said. "It does have some restriction and there is some notice given depending on what kind of facility it is, but it has certainly expanded access."
Ms. Fleming said the IAEA would need to give two hours notice to visit a nuclear facility and 24 hours for other locations.
A resolution passed by the IAEA board in September went beyond this, and called on Iran to allow unrestricted access, including environmental sampling, to whatever locations the agency deems necessary.
The IAEA says such wide area sampling would normally need a mandate from the board of governors and is not covered by the additional protocol.
The board of governors meets at the end of November to assess if Iran is complying with its resolution or if Iran's nuclear program should go before the U.N. Security Council.