(Reuters) - The U.N. atomic agency says it needs about 4.6 million euros ($5.67 million) more from member states to finance monitoring of an extended nuclear deal between Iran and six world powers, a document seen by Reuters said on Wednesday.

Iran and the United States, FranceGermany, Britain, China, and Russia failed to meet a Nov. 24 deadline for resolving a 12-year dispute over Iran's nuclear program and gave themselves until the end of June for further negotiations.

As a result, a preliminary agreement reached late last year, under which Iran halted its most sensitive nuclear activity in exchange for limited sanctions easing, will remain in force.

The International Atomic Energy Agency (IAEA) is tasked with checking that Iran meets its commitments under the accord.

In a confidential note to member states ahead of an extraordinary IAEA board meeting next week to discuss the issue, the U.N. agency said it estimated the cost of its extended monitoring work at about 5.5 million euros.

To raise this amount, it said, "an additional amount of 4.6 million euros of voluntary extra-budgetary contributions would be required.”