BRASÍLIA, May 10 - Leaders of South America and the Arab world, two regions that have had relatively little contact with each other but have long chafed at American dominance, gathered here on Tuesday to meet for the first time and to air their list of grievances.

But the two blocs in attendance at the initial South American-Arab Nations Summit almost immediately voiced profoundly different priorities. In their opening speeches, President Abdelaziz Bouteflika of Algeria and Amr Moussa, secretary general of the Arab League, focused their criticisms on Israel and the United States and called for greater solidarity with the Palestinians.

South American leaders, however, sought to keep the emphasis on economic issues. "Our great challenge is to design a new international economic and commercial geography," the Brazilian president, Luiz Inácio Lula da Silva, said in remarks inaugurating the event on Tuesday morning.

The conference is a Brazilian initiative, part of a larger effort by the government of Mr. da Silva to project Brazil onto the world stage as a regional power and to secure a permanent seat on the United Nations Security Council. It comes on the heels, however, of some embarrassing foreign policy missteps, like the collapse of Brazil´s bid to lead the World Trade Organization and a tiff with neighboring Argentina.

Attendance fell short of Brazil´s initial expectations, further depriving the event of some of its luster. While the majority of South America´s 12 presidents are participating, only 7 of the 22 Arab nations that were invited are represented by heads of state or government.

One of them was the new president of Iraq, Jalal Talabani, who was making his first trip abroad in that capacity. His presence and that of the president of the Palestinian Authority, Mahmoud Abbas, accounted for the extraordinary security precautions that had an estimated 9,000 soldiers and police officers in the streets of the Brazilian capital and shut down normal activities here.

Behind the scenes, the two blocs struggled to devise a final declaration that would be acceptable to both sides and not damage Brazil´s diplomatic aspirations. Diplomats here said the United States and the European Union had expressed concerns to participants at the tone of the draft that the Arab group were pushing with some support from Venezuela´s president, Hugo Chávez, Washington´s leading critic in South America.

On Tuesday, a spokesman for the Israeli Foreign Ministry, Mark Regev, expressed hope that "our many friends in South America" would help avoid "some sort of extreme one-sided declaration that has no positive impact on the peace process" and just encourages militant groups. Brazil´s foreign minister, Celso Amorim, who is expected to visit Israel soon, said before the conference that he saw "no reasons for the United States to be concerned."

As of Monday night, the joint declaration called on Israel to withdraw to its pre-1967 borders and to dismantle its West Bank settlements, including those in East Jerusalem, and included language condemning terrorism, according to a draft made available to The New York Times.

But it also called for an international conference to define what terrorism is, and endorsed the right of peoples to "resist foreign occupation in accordance with the principle of international legality and in compliance with international humanitarian law." (Copyright 2005 The New York Times Company 05/11/05)