JERUSALEM: Israel's Chief-of-Staff Lieutenant General Benny Gantz does not believe Iran will take the decision to build a nuclear bomb, he told an Israeli newspaper in an interview published on Wednesday.

Speaking to the left-leaning Haaretz newspaper, Gantz said Iran was going “step-by-step to the place where it will be able to decide if it wants to manufacture a nuclear bomb.

“It still hasn't decided yet whether to go the extra mile,” he said, expressing a view also held by the administration of US President Barack Obama.

Iran has already developed the capacity to enrich uranium to 20 percent, which is used to create medical isotopes, but going “the extra mile” would mean working to enrich to 90 percent — the level needed to make nuclear weapons.

“If the supreme religious leader Ayatollah Ali Khamenei wants, he will move forward towards acquiring a nuclear bomb, but the decision must first be taken,” he said.

“In my opinion, he would be making a huge mistake if he does so, and I don't think he will want to go the extra mile,” Gantz said.

“I think that the Iranian leadership is made up of very rational people.” Israel and much of the West suspect Iran is using its civilian nuclear programme as a cover for a weapons drive — a charge which Tehran vehemently denies.

In recent months, there have been growing concerns the Jewish state might launch a pre-emptive military strike on Iran in a bid to destroy, or at least severely disable, its nuclear programme.