A confidential document from the U.N.'s atomic agency says the extra work related to monitoring Iran's compliance with last month's nuclear deal will cost about 9.2 million euros ($10.5 million) each year.

The International Atomic Energy Agency document obtained by The Associated Press also estimates the final tab will be nearly 138 million euros ($157 million) over the life of the pact.

Drawn up for a special IAEA meeting Tuesday, the document says the costs are calculated from the time the deal begins to be implemented, at some point after it is adopted on Oct 18.

The document extrapolates the total cost by saying the estimated annual cost of 9.2 million euros is "foreseen as being applicable for 15 years." That is the expected duration of the Iran deal.