Leon Panetta

ASHKELON, Israel — U.S. Defense Secretary Leon Panetta said today that Iran must either negotiate acceptable limits on its nuclear program or face the possibility of U.S. military action to stop it from getting the bomb.

Panetta made his remarks outside the city of Ashkelon in southern Israel, with an “Iron Dome” anti-rocket defense system as a backdrop.

The Pentagon chief said repeatedly that “all options,” including military force, are on the table to stop Iran, should sanctions and diplomacy — the preferred means of persuasion — ultimately fail.

He said he still hopes Iran will see negotiations are the best way out of this crisis.

However, Panetta said, “If they continue and if they proceed with a nuclear weapon, ... we have options that we are prepared to implement to ensure that that does not happen.”

Israeli Defense Minister Ehud Barak, standing beside Panetta, said he sees an “extremely low” probability that sanctions will ever compel Iran to give up its nuclear activities.

Barak said Israel “has something to lose” by waiting for sanctions and diplomacy to run their course because Iran is continually accumulating enriched uranium as the key ingredient for a nuclear bomb.

Iran says its nuclear work is for civilian energy uses, but suspicions that the Islamic republic will use enriched uranium for nuclear weapons have resulted in international sanctions and saber-rattling from Israel, which perceives a nuclear Iran as an existential threat. The United States has discouraged Israel from a unilateral, pre-emptive military strike on Iran, but has said it would keep all options available.

The Panetta visit with his Israeli counterpart comes just days after U.S. Republican presidential hopeful Mitt Romney met with top Israeli officials about Iran and other issues. Romney has accused the Obama administration of being too soft on Iran and not providing sufficient support to Israel.

In greeting Panetta today at Israeli defense headquarters, Barak said, “The defense ties between Israel and the United States are stronger and tighter than they have ever been and the credit now has to go, most of it, to you, Leon.”

Panetta responded: “We are a friend, we are a partner, we have, as the defense minister has pointed out, probably the strongest U.S.-Israel defense relationship that we have had in history. What we are doing, working together, is an indication not only of our friendship but of our alliance to work together to try to preserve peace in the future.”

Prime Minister Benjamin Netanyahu said both Romney and Obama have said “Israel has the right to defend itself.”