Financial Tribune- Former US secretary of defense, Leon Panetta, said the most powerful non-nuclear weapon, GBU-43, was considered a good option to be deployed for possible attacks on Iran's nuclear facilities when he was in office, from 2011 to 2013. "When I was secretary of defense, we were working on developing that weapon.

Very frankly, the weapon was initially targeted at the potential of going after underground enrichment facilities in Iran, which was our concern," Panetta told MSNBC about the development of the bomb, the so-called "mother of all bombs".

The US used the bomb against a stronghold of the self-styled Islamic State terrorist group in Afghanistan on Thursday. "It is a weapon that can be used effectively, as it was in Afghanistan, to go after IS fighters located in deep caves. I think that is a good use of the weapon," Panetta said during an interview on Friday.