Republican presidential candidate Mitt Romney on Sunday evening reiterated his commitment to preventing Iran from acquiring nuclear weapons at a much-awaited policy speech in Jerusalem. He also affirmed his unwavering commitment to Israel.

“It’s a deeply moving experience to be in Jerusalem, the capital of Israel,” said Romney to a standing ovation.

“When Iran’s leaders deny the Holocaust or speak of wiping this nation off the map, only the naïve – or worse – will dismiss it as an excess of rhetoric,” he said in an outdoor Jerusalem venue. “Make no mistake: the ayatollahs in Tehran are testing our moral defenses. They want to know who will object, and who will look the other way. My message to the people of Israel and the leaders of Iran is one and the same: we will not look away. Nor will my country ever look away from our passion and commitment to Israel.”

Addressing about 250 invited guests at the Mishkenot Sha’ananim center, overlooking Jerusalem’s Old City walls and the iconic windmill of Moses Montefiore, Romney quoted former Israeli prime minister Menachem Begin, saying, “If an enemy of the Jewish people says he seeks to destroy us — believe him. We have seen the horrors of history. We will not stand by. We will not watch them play out again. It would be foolish not to take Iran’s leaders at their word. They are after all the products of a radical theocracy.”

“It is my firm conviction that the security of Israel is in the vital national security interest of the United States,” Romney said to roaring applause. “Ours is an alliance based not only on shared interests but also on enduring shared values. In those shared values, one of the strongest voices is that of your prime minister, Benjamin Netanyahu.”

“Whenever the security of Israel is most in doubt, the American commitment to Israel must be most secure,” he said to standing ovations.

In line with a longstanding tradition not to attack the sitting president on foreign soil, Romney refrained from criticizing too harshly — or even mentioning — President Barack Obama, whom he will face in the November elections. Romney did say, however, that “diplomatic distance in public between our nations emboldens Israel’s adversaries,” in what observers understood aimed at the Obama’s administration. In the past, Romney accused Obama of “throwing Israel under a bus.”

Speaking on a podium adorned with a photo of an American and an Israeli flag and the words “Freedom and Democracy,” both in Hebrew and in English, the former Massachusetts governor recalled an address he gave five years ago at the Herzliyah conference on Israeli security. “I stated my view that Iran’s pursuit of nuclear weapons capability presents an intolerable threat to Israel, to America, and to the world. That threat has only become worse. Now as then, the regime’s claims that it seeks to enrich nuclear material for peaceful purposes are belied by years of malign deceptions. Now as then, the conduct of Iran’s leaders gives us no reason to trust them with nuclear material.

“But today,” he continued, “the regime in Iran is five years closer to developing nuclear weapons capability. Preventing that outcome must be our highest national security priority.”

Romney was speaking as the Tisha B’Av fast, which commemorates the destruction of Jerusalem’s First and Second Temples, wound down. Many of the attendees still sported three-week beards, as observant Jews refrain from shaving in the weeks and days ahead of the fast. Romney spoke to a select group of prominent Israelis, among them Jerusalem Mayor Nir Barkat, and to donors including Jewish American billionaire Sheldon Adelson, who has supported Romney’s campaign to the tune of millions of dollars.

In his 18-minute speech, Romney also paid tribute to the 11 Israeli athletes who where murdered by Palestinian terrorists 40 years ago at the Olympics in Munich, and to nine Israeli and foreign students who were killed during a terrorist attack at the Hebrew University exactly 10 years ago this week.

It was the only public address he made during his whirlwind Israel visit, which formally concludes Sunday night with a dinner hosted by Prime Minister Netanyahu and his wife Sarah at the Prime Minister’s Residence in Jerusalem. Romney’s next stop before returning to the US is Poland.