An Israeli official said that "there's never a 100 percent guarantee," but "a nuclear disaster" should "not happen."

Those proposals mirror those previously floated by Iran in confrontations with either Israel or the United States in that last few decades.

Roughly 140 miles south of Tehran, Natanz is considered Iran’s main center for uranium enrichment, and it was a prime target of the Israeli strikes. The damage to it appeared to be severe. It is only partially underground and was recently reinforced.