Iran is ready to give the International Atomic Energy Agency "full supervision" of its nuclear program for five years if U.N. sanctions are lifted, its nuclear chief said in remarks published Monday.

"We have proposed that the agency keep
Iran 's activities and nuclear program under full supervision for five years, providing the sanctions are lifted," the nuclear chief, Fereydoun Abbasi Davani, told ISNA news agency.

Iran is targeted by four sets of U.N. Security Council sanctions over its refusal to suspend uranium enrichment amid fears in the West that it seeks to build a nuclear bomb--a charge it vehemently denies.

Abbasi Davani neither said when the offer was made to the IAEA, nor what he meant by "full supervision."

Much of
Iran 's nuclear activities are already under the control of the IAEA, including uranium enrichment--a process that can both produce the fuel for a nuclear reactor and the fissile material for an atomic warhead.

The IAEA said in a confidential report that it is "increasingly concerned about the possible existence in
Iran of past or undisclosed nuclear related activities involving military related organizations."

These included "activities related to the development of a nuclear payload for a missile", according to the report, which is due to be discussed by the IAEA's 35-member board of governors at a Sept. 12-16 meeting.

But Abbasi Davani said such allegations are "baseless and fabricated."

The agency has for years criticized
Tehran for refusing to answer a number of questions about its nuclear program, and for denying access to certain sites, including the heavy water reactor Iran is building in the central city of Arak .