Iran has not signed the Addional Protocol, so it is in its right not to abide with that. By a similar logic, Israel has not signed the NPT, so they are allowed to have nuclear weapons. You can't have it both ways. If Israel is not bound by treaties it did not sign, neither is Iran.
Colombia recalls ambassador to Venezuela amid border crisis (Reuters)
from the article: U.S. awaiting formal response from Iran on nuclear draft deal