VIENNA (AP) � A senior diplomat says a landmark Iran nuclear agreement was reached Tuesday after clearing final obstacles. The diplomat says it includes a compromise between Washington and Tehran that would allow U.N. inspectors to press for visits to Iranian military sites as part of their monitoring duties.

But access at will to any site would not necessarily be granted and even if so, could be delayed, a condition that critics of the deal are sure to seize on as possibly giving Tehran time to cover any sign of non-compliance with its commitments.

Under the deal, Tehran would have the right to challenge the U.N request and an arbitration board composed of Iran and the six world powers that negotiated with it would have to decide on the issue.

By AP