The recent U.S. sanctions on the chief of Atomic Energy Organization of Iran (AEOI) would not affect the progress of the country's nuclear program, Iran's Foreign Ministry Spokesman Abbas Mousavi said Friday.

"It is not for the first time that he (AEOI chief Ali Akbar Salehi) is targeted by the illegal and unilateral (U.S.) sanctions," Mousavi said.

"Sanctions on him is out of desperation," he added.

On Tuesday, U.S. Treasury announced that it had slapped sanctions on the AEOI and its head Salehi amid tension with Iran.

The spokesman for AEOI later dismissed the U.S. sanctions as "desperate" attempt and "worthless."