Israel has not promised to refrain from military strikes on Iran's nuclear facilities during the course of Tehran's negotiations with the world powers, Defense Minister Ehud Barak said on Tuesday.

"I do not believe the efforts (of the international community) to stop Iran's nuclear program will bear fruit," Barak said in an interview with Army Radio on Tuesday morning.

"We are not part of the negotiations, but we think that the Americans have an objective to stop Iran ... the chance for success isn't high," said Barak, who was due to depart Colombia for Washington, where he is expected to meet with his U.S. counterpart Leon Panetta.

The defense minister's comments echoed those of other senior Israeli officials who had criticized the preliminary nuclear deliberations between Iran and the six world powers - the United States, Russia, China, Germany, Britain and France - in Istanbul on Saturday, which ended with a decision to convene a second round of talks in Baghdad on May 23.

"My initial impression is that Iran has been given a freebie. It now has five weeks to continue (uranium) enrichment without any limitation," Prime Minister Benjamin Netanyahu said Sunday in the first official statement from Israel on the talks.

Netanyahu, who said Iran is using the discussions to gain time, reiterated Israel's demands for a satisfactory diplomatic resolution to the dispute over Tehran's nuclear ambitions: an immediate cessation of all enrichment, high and low; the removal of existing nuclear fuel stockpiles; and the dismantling of the Fordo nuclear research facility near Qom.