U.S. Secretary of Defense Leon Panetta on Wednesday reiterated his country's commitment to curbingIran's nuclear program, warning that Washington is prepared to use "other options" to ensure Tehran does not obtain an atomic bomb.

"We,Israeland theUnited States, share deep concerns about the violence taking place inSyriaand Iran's nuclear ambitions. I want to reassert again that with regards to Iran, we will not allow Iran to develop nuclear weapons," Panetta said at a joint press conference with Prime Minister Benjamin Netanyahu in Jerusalem on Wednesday.

"I want the people of Israel to know that the U.S. stands firmly with them. We have rock-solid commitment to Israel and its security. We will remain determined to prevent Iran from acquiring nuclear weapons."

The remarks highlighted a two-day visit by the defense secretary, who arrived here on Tuesday evening for high-level talks in which Iran's disputed nuclear program figured prominently.

Speaking before Panetta, Netanyahu asserted that "no challenge is greater" than stopping Iran's pursuit of nuclear weapons, and warned that "time was running out" on a peaceful solution to the issue.

"Iran believes that the international community does not have the will to stop them. The world must convince Iran very soon that it is serious and that Iran will face unacceptable consequences if it keeps building its nuclear weapons program," Netanyahu said.

Earlier Wednesday, Panetta and his Israeli counterpart, Ehud Barak, visited an Iron Dome anti-missile defense battery deployed outside the coastal city of Ashkelon.

Palestinian militants in the Gaza Strip have fired hundreds of rockets into the city over the last few years, some of which hit hospitals and populated civilian areas.

Addressing a press conference at the site, Panetta said that the United States is prepared to resort to military force to stop Iran's pursuit of a nuclear weapon.

"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," Panetta said.

"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," he said, underscoring that the United States respects Israel's right as a sovereign nation to defend itself.

Upon departing from meetings in Cairo on Tuesday, Panetta said that he and Barak would be covering "various contingencies," but demurred as to whether the two planned to discuss "potential attack plans" against Iran or Syria, according to The Jerusalem Post.

"The discussions that I hope to have with Israel are going to be more about the nature of the threat that we're confronting and to try to share both information and intelligence on that," he said.

Barak, standing beside Panetta for a photo-op at the Iron Dome site on Wednesday, responded to PresidentBarack Obama's announcement of two new rounds of sanctions against Tehran the previous day, expressing skepticism that they would bear fruit.

"Diplomacy takes time, but at the same time, the Iranians continue to enrich uranium... We have everything to lose while time passes allowing diplomacy to work," the Ha'aretz daily quoted Barak as saying.

In a meeting with Panetta at the Defense Ministry's headquarters in Tel Aviv, Barak alluded to "disagreements and differences of opinion" between the allies, possibly over what stage of Iranian nuclear fuel enrichment would constitute a " threshold" for a separate or combined Israeli or American military strike.

Barak, however, hailed what he termed "the profound depth" of the Israeli-U.S. alliance, noting that bilateral security ties are "stronger and tighter than ever."