The deep penetrating bombs that the U.S. dropped into two Iranian nuclear facilities were designed specifically for those sites and were the result of more than 15 years of intelligence and weapons design work.

Iran's foreign minister has admitted that "excessive and serious" damage was done to the country's nuclear sites in the recent US and Israeli bombings. Abbas Araghchi told a state broadcaster on Thursday evening,

U.S. strikes on Iranian nuclear sites inflicted "serious and significant damage," Iran has acknowledged for the first time since the attack nearly a week ago.