(CNN) -- Israel's top general said Iran is led by "very rational people" and doesn't appear poised to build a nuclear bomb that would threaten his nation.
Iran "is going step by step to the place where it will be able to decide whether to manufacture a nuclear bomb," Chief of Staff Lt. Gen. Benny Gantz told Israel's Haaretz newspaper in Wednesday editions. "It hasn't yet decided whether to go the extra mile."
The head of Israeli Defense Forces set a different tone than that of Prime Minister Benjamin Netanyahu, who suggested to CNN on Tuesday that time is running out for Western sanctions on Iran to have a meaningful effect on Tehran's nuclear program.
The sanctions "are certainly taking a bite out of the Iranian economy," Netanyahu said in an interview broadcast Tuesday on CNN's "OutFront." But "they haven't rolled back the Iranian program -- or even stopped it -- by one iota."
"I hope that changes, but so far, I can tell you, the centrifuges are spinning," he said. "They were spinning before the talks began recently with Iran, they were spinning during the talks, they're spinning as we speak."
Key world powers met with Iran earlier this month about Tehran's intentions for its nuclear program and announced that the next meeting would take place in late May. Iran maintains it is not planning to build a bomb.
Iranian Ayatollah Ali Khamenei, according to Gantz, likely won't build a bomb if he believes his facilities are vulnerable to Israeli attack.
"I think the Iranian leadership is composed of very rational people," Gantz told Haaretz. "But I agree that such a capability, in the hands of Islamic fundamentalists who at particular moments could make different calculations, is dangerous."
The chief of staff said the military is preparing for all possible scenarios.
The United States and European nations have imposed tough economic sanctions on Iran in an effort to pressure it into accepting international demands to restrict its nuclear program.
"If the sanctions are going to work, they better work soon," Netanyahu said on CNN.
Iran insists that its nuclear program is for energy and medical purposes. U.N. and Western leaders suspect it of having military aims, including a possible nuclear weapon.
Last month, the International Atomic Energy Agency, the U.N. nuclear watchdog, noted what it called a sharp and troubling increase in Iran's uranium enrichment capabilities.
The talks with Tehran this month involved the five permanent members of the United Nations Security Council -- the United States, France, Russia, China, and Britain -- as well as Germany.
That group has spearheaded diplomatic efforts to persuade Iran to rein in its nuclear program, but Israel has criticized the initiative as giving too much ground to Tehran and demanded that it stop all enrichment activities.
Netanyahu said that if the combination of sanctions, diplomacy and "other pressures" succeeds in stopping Iran's nuclear program, "I will be the happiest person in the world."