According to US intelligence estimates, the strikes on Iran's nuclear sites have delayed the country's nuclear programme by up to two years, AFP reports.

"We have degraded their program by at least one to two years - the intelligence estimates in the Department of Defense assess that," Pentagon spokesman Sean Parnell said. "We think it will probably be closer to two years," he added.

Last month, US B-2 bombers struck two Iranian nuclear sites with GBU-57 bunker buster bombs. A guided-missile submarine hit a third site with Tomahawk cruise missiles.

On June 13, Israel launched an unprecedented air campaign targeting Iranian nuclear sites, scientists and senior military officials in an attempt to end the country's nuclear program, which Tehran says is for civilian purposes but Washington and other powers insist is aimed at acquiring atomic weapons.

The U.S. operation was large-scale and involved more than 125 U.S. aircraft, including stealth bombers, fighter jets and air refueling tankers, as well as a guided missile submarine. | BGNES