An Americas summit the United States had hoped to use to bolster prospects for a free trade zone in the Western Hemisphere ended without bridging a gap between North and South America, where key governments remain wary of the proposal.

Thirty-four heads of state and government flew home from this Argentine resort town without agreeing on a specific date for resuming negotiations on the Free Trade Area of the Americas, initially proposed by the United States in 1994.

Instead, their surrogates signed a final declaration on fighting poverty that included an annex with opposing viewpoints on the trade initiative.

Twenty-nine countries said they wanted to resume negotiations on the FTAA in 2006. But five countries, including Brazil, Argentina and Venezuela, stated their opposition to the deal.

"Necessary conditions are not yet present to reach an equitable and balanced hemispheric free trade accord free of subsidies and distorting trade practises ... and taking into account the needs and sensibilities of all the members," a text of the annex read.

It said members had agreed to "explore both positions" following the next round of World Trade Organization talks in Hong Kong in December, possibly at a trade-minister-level meeting in Colombia.

Putting the best face on the outcome, Chilean Foreign Minister Rafael Bielsa said his government was satisfied with the results of the summit.

"It"s not a defeat for the FTAA," he assured.

From a plane taking US President George W. Bush from Argentina to Brazil, US national security adviser Stephen Hadley insisted the summit had made "real progress" toward expanded trade, despite its failure to reach a unified stance.

"We went from a summit which was supposed to bury FTAA to a summit in which all 34 countries actually talk in terms of enhanced trade ... recognizing there are challenges," Hadley told reporters. "I would say that is some real progress."

Hadley said the US president believed that the exchange among the leaders that had taken place was important.

"He thinks it"s important to have a free flow of exchange among the leaders, and that all the leaders have an opportunity to speak," Hadley said of Bush. "There is nothing in stone that says every time leaders get together they have to have a summit communique."

The two-day summit in the Atlantic resort of Mar del Plata highlighted the political polarization that has occurred since the end of the Cold War, as Latin American countries, including key nations Argentina, Brazil, Chile and Venezuela, shifted toward the left.

Venezuelan President Hugo Chavez, a frequent and outspoken critic of the United States, has led the charge against the FTAA, vowing to a crowd of 40,000 demonstrators Friday that he would "bury" it.

On Saturday, he told AFP that Venezuela and Mercosur, the trade bloc that includes Brazil, Argentina, Uruguay and Paraguay, would stand "like a rock" against mentioning the FTAA in the summit"s final declaration.

Brazilian President Luiz Inacio Lula da Silva, visibly annoyed, insisted that the FTAA was not supposed to be on the agenda.

"When I was invited to this meeting, there were three themes to discuss: jobs, jobs and jobs. Nowhere was the FTAA mentioned," Lula told reporters.

Panama proposed a text calling for FTAA talks to be held "in the course of 2006," instead of Mexico"s call for a ministerial-level meeting to be scheduled early next year. But sources involved in the negotiations said Mercosur refused to budge.

The uproar over the FTAA totally overshadowed what was supposed to be the theme of this fourth Summit of the Americas: the fight against poverty and unemployment.

Violent anti-US protests erupted Friday, on the opening day of the summit, held in the luxury Hermitage Hotel.

Riot police fired tear gas on hundreds of rock-throwing demonstrators who tried to breach the summit"s security perimeter. Protesters roamed the streets downtown, throwing Molotov cocktails, lighting bonfires and smashing shop windows for some 90 minutes before security forces restored order.

Police said 64 people were arrested in the mayhem, and eight were arrested in Buenos Aires in similar violent protests.