Asked whether the negotiations, which began in Turkey on Saturday, could persuade Iran to halt uranium enrichment, Ehud Barak told Army Radio: “It does not look to me as if it is going to happen — not now, in the wake of Istanbul, and not... after the (Baghdad round of talks next month).”

Iran’s President Mahmoud Ahmadinejad warned yesterday that his country’s armed forces will make its enemies regret any act of aggression against the Islamic Republic.

“The armed forces and the army will inflict heavy regret and shame in case of any aggression against Iranian lands and interests,” Ahmadinejad told military commanders and personnel on the occasion of Iran’s annual Army Day.

Barak is due to meet US Defense Secretary Leon Panetta in Washington on Thursday amid speculation in the Israeli media that Israel has promised its main ally that it will refrain from attacking Iran while the talks continue.

“We are not committing to anything,” Barak said, when asked whether any such pledge had been made. “There is not, there has not been, there should not be and there cannot be (such a promise).”

Barak has said that Iran could soon enter a “zone of immunity” against Israeli attack as it puts its nuclear installations deep underground, comments that raised international concern that a strike could be nearing.

In the interview, he reiterated Israeli fears that the negotiations between Iran and a group comprising the United States, Britain, France, China, Russia and Germany could drag on and waste what he described as “precious time.”

On Sunday, Prime Minister Benjamin Netanyahu appeared to open a rift with Washington over the talks by saying that a five-week break between the Istanbul meeting and the next session in Baghdad on May 23 gave Iran a “freebie” to continue enriching uranium.

US President Barack Obama, responding to Netanyahu’s accusations, said “so far at least we haven’t given anything away” and that it had been made clear to Iran that “the clock is ticking” and there could be no “stalling process.”

Israel and the West fear Iran’s nuclear program is aimed at producing atomic weapons. Iran says it is enriching uranium for peaceful purposes.