Ayatollah Yousef Sanei, a close associate of the late Ayatollah Ruhollah Khomeini, criticized Ahmadinejad for "unnecessarily spurring international enmity" toward Iran, the Washington Times reported.
"We must bear in mind that not everyone is our enemy," Ayatollah Sanei told the Kargozaran newspaper. "Undue enmity with enemies does not serve the interests of the system."
The newspaper said unelected clerics hold ultimate authority in Iran.
Former CIA official Graham Fuller says the "upper echelons" of Iran want to cut back Ahmadinejad's powers.
"There's a clear recognition that he has made too many enemies and abandoned the smarter previous policies of seeking to divide the (European Union) from the (United States) and not unite them," he told the Washington Times.