TEHRAN -- A senior Iranian nuclear official on Tuesday hit out at the head of the International Atomic Energy Agency (IAEA) for renewing claims about “undeclared” nuclear sites in Iran, saying Tehran has already had “maximum cooperation” with the UN nuclear agency to help resolve the situation.Spokesman for the Atomic Energy Organization of Iran (AEOI) Behrouz Kamalvandi reacted to comments Grossi made on Monday, the first day of a quarterly meeting of the IAEA Board of Governors. Iran, he said, has been fully cooperative regarding the three alleged sites brought up by the Agency and has sent information and answers to the IAEA’s questions and has also held meetings to resolve the ambiguity.