The White House Wednesday insisted sanctions against Iran were having a “significant” impact after Israeli Prime Minister Binyamin Netanyahu said they had not set back Tehran’s nuclear plans. President Barack Obama’s spokesman Jay Carney said Iran had “yet to make the choice it needs to make, which is to abandon its nuclear weapons ambitions.” “We completely agree with the prime minister’s assessment that Iran has failed to make that choice and that is absolutely a disappointment,” Carney said, aboard Air Force One. He added however that sanctions were having “a significant effect on the Iranian economy.” Netanyahu said on Sunday that the recently tightened sanctions against Iran and stalled international talks had “not set back the Iranian program by one iota,” as he met Republican presidential hopeful Mitt Romney. He returned to the issue on Wednesday as he met US Defense Secretary Leon Panetta in Jerusalem. “You recently said that sanctions on Iran are having a big impact on the Iranian economy, and that is correct,” Netanyahu told Panetta. “But unfortunately it is also true that neither sanctions nor diplomacy have yet had any impact on Iran’s nuclear weapons programme. “You yourself said a few months ago that when all else fails, America will act. But these declarations have also not yet convinced the Iranians to stop their programme,” he warned. “However forceful our statements, they have not convinced Iran that we are serious about stopping them,” Netanyahu said. On Tuesday, Obama tightened sanctions against Iran, targeting Tehran’s oil export sector and a pair of Chinese and Iraqi banks accused of doing business with the Islamic Republic. Iran denies that its nuclear programme has a military purpose.