MIAMI -- President Bill Clinton and the leaders of 33 Western Hemisphere nations have signed a free-trade agreement that Clinton called "a watershed in the history of the hemisphere."


The leaders, at the close of the weekend's Summit of the Americas, promised Sunday that the 32-page document, which agrees to create the largest free-trade zone in the world, will mean more jobs and prosperity for the region's citizens.


Under the agreement, the presidents and prime ministers of Canada, Latin America and the Caribbean resolved to begin building the Free Trade Area of the Americas immediately, and to conclude talks no later than the year 2005.


While lavishing praise on the symbolism and promise of the summit, most officials acknowledged that the pact is only the beginning of a long and ambitious process. But several said they hoped the fact that the United States sat down with the rest of the hemisphere -- the first such meeting in 27 years -- signaled the start of a new relationship.


There were also words of caution about the difficulties that lie ahead, as the new zone requires a number of countries to reform sluggish economic systems, reduce high tariffs, eliminate subsidies and set up legal mechanisms to guarantee property rights.