President Clinton pleaded with the leaders of Latin America on Thursday to be patient with the United States as it conducts a painful internal political debate over the merits of free trade throughout the hemisphere.

Clinton, in Chile for a Latin American summit meeting dedicated to creating a hemispheric duty-free shop from the Yukon to Tierra del Fuego, felt compelled to explain Congress' refusal last fall to grant him unlimited trade negotiation authority, known as "fast track."In a speech to an international business audience here on Thursday, Clinton acknowledged that he had so far failed to convince a majority in Congress of the benefits of free trade with the other nations of the hemisphere. The United States currently has a free-trade pact with Mexico and Canada.

Clinton said that ultimately the United States would not walk away from the "colossal opportunity" presented by the so-called Free Trade Area of the Americas, which is supposed to be in place by 2005.

Clinton quoted Winston Churchill, who said, "The United States invariably does the right thing, after having exhausted every other alternative."

The president said: "So be patient with us. So just stay with us. We'll get there."

Clinton said he would continue to press for approval of fast-track authority, under which Congress can approve or reject proposed trade treaties negotiated by Clinton but cannot amend them. The presidential authority is considered crucial to achieve trade breakthroughs because other countries will be reluctant to negotiate trade deals with the United States if they feel Congress will change the terms after an agreement is reached.

A bill granting Clinton fast-track authority was withdrawn last November after Democrats in Congress said they were not convinced that the trade deals the president is proposing would provide adequate protection for workers and the environment.