JERUSALEM — Mitt Romney offended Palestinian leaders on Monday by suggesting that cultural differences explain why the Israelis are so much more economically successful than Palestinians, thrusting himself again into a volatile issue while on his high-profile overseas trip.


His remarks drew a pointed rebuke from the Palestinian leadership, which angrily noted that Mr. Romney had failed to mention the years of trade restrictions imposed by Israel.


The comments came after he questioned London’s preparations for the Olympic Games while in that city, drawing criticism from the British prime minister and others. And they once again overshadowed a trip that was designed to show his dexterity on the foreign policy front, as his remarks put him in the choppy crosscurrents of Israel-Palestinian affairs where American presidents have often served as mediators.


This time, Mr. Romney did not seek to recalibrate his remarks, as he did in Britain, and the comments, made at a fund-raiser with prominent Jewish-American backers, came as he has been trying to show his fealty to the Israeli cause and slice into President Obama’s Jewish support.


In the speech, Mr. Romney mentioned books that had influenced his thinking about nations — particularly “The Wealth and Poverty of Nations,” by David S. Landes, which, he said, argues that culture is the defining factor in determining the success of a society.


“Culture makes all the difference,” Mr. Romney said. “And as I come here and I look out over this city and consider the accomplishments of the people of this nation, I recognize the power of at least culture and a few other things.”


He added, “As you come here and you see the G.D.P. per capita, for instance, in Israel, which is about $21,000, and compare that with the G.D.P. per capita just across the areas managed by the Palestinian Authority, which is more like $10,000 per capita, you notice such a dramatically stark difference in economic vitality. And that is also between other countries that are near or next to each other. Chile and Ecuador, Mexico and the United States.”


The remarks, which vastly understated the disparities between the societies, drew a swift rejoinder from Palestinian leaders. In an interview with The Associated Press, Saeb Erekat, a senior aide to President Mahmoud Abbas of the Palestinian Authority, called Mr. Romney’s remarks racist.


“It is a racist statement and this man doesn’t realize that the Palestinian economy cannot reach its potential because there is an Israeli occupation,” Mr. Erekat said. “It seems to me this man lacks information, knowledge, vision and understanding of this region and its people.”


Mr. Romney did not speak to the deleterious impact of deep Israeli trade restrictions on the Palestinian economy, an effect widely described by international organizations including the World Bank, which recently reported that “the government of Israel’s security restrictions continue to stymie investment.”


The comments are likely to have little if any domestic political repercussions for Mr. Romney, but Obama campaign officials charged that they could hurt Mr. Romney’s chances to ever play a credible role in the Middle East peace process, a complicated and highly charged undertaking where even mild nuances in language are microscopically examined and can take on far larger significance.


The argument comparing Israeli and Palestinian vitality is one Mr. Romney has made previously — in speeches and in his book “No Apology” — and one that he has used to explain economic disparities between other countries, as well.


But the comments on Monday, made at a fund-raiser at which Mr. Romney was seated next to Sheldon Adelson, the billionaire Republican backer, was widely circulated after The Associated Press published Mr. Romney’s remarks along with the response by Mr. Erekat. Throughout the day, Mr. Romney’s aides were grim-faced and exasperated as they tried to contain the aftermath of what Stuart Stevens, a senior strategist, called “a completely manufactured story.”


“This was not in any way an attempt to slight the Palestinians and everyone knows that,” Mr. Stevens said.


Paul Colford, the director of media relations for The Associated Press, said the organization stood by its account, which the Romney campaign described as “grossly mischaracterized.”


The candidate’s remarks came four days after he drew pointed barbs from the British prime minister, David Cameron, and London’s mayor, Boris Johnson, by questioning the city’s preparedness and enthusiasm for the Olympics.