JERUSALEM—An Israeli news program claims that Israel's premier told his military to prepare for a strike on Iranian nuclear sites in 2010, but it was not ready.

Defense Minister Ehud Barak says in excerpts aired Sunday that "at the moment of truth, the answer given was that the ability didn't exist."

It quotes former Mossad chief Meir Dagan as telling Prime Minister Benjamin Netanyahu that the order was illegal, as it needed Cabinet approval.

The full program is scheduled for broadcast Monday.

Israel views Iran as an existential threat due to its nuclear program, frequent calls for Israel's destruction and support of anti-Israel militants.

The West suspects Iran might try to build nuclear weapons. Iran denies that. Israel has hinted at a military strike if economic sanctions fail.