By FRANCES ROBLES

Visits to Latin America by Obama administration officials started out like a trickle, and now they're a full-fledged stream.

The secretary of state, attorney general and head of homeland security are all taking trips to Mexico this month, and President Barack Obama will stop there on the way to a regional summit in Trinidad in April.

Vice President Joe Biden will meet Friday and Saturday with South American leaders in Chile before he heads to Costa Rica for another two-day meeting with Central American heads of state.

The visits underscore Obama's interest in addressing regional issues despite other, more pressing crises, experts say. Biden's two-country tour following the series of Cabinet-level meetings show Obama is trying to diversify his approach to Latin America so that he does not concentrate on the drug-fueled violence in Mexico at the expense of other nations, experts said.

For a region suffering the economic fallout from the U.S. recession and experiencing a surge of democratically elected leaders hostile to Washington, the trips are critical.

''This is really important -- these visits are overdue,'' said Carmen Diana Deere, director of the Center for Latin American Studies at the University of Florida. ``Expectations in Latin America are tremendously high that Obama will offer significant change in policy in favor of a partnership with Latin America.''

Biden makes his first official trip to Latin America this weekend, attending a summit in Chile where he and like-minded center-left politicians will seek solutions to the global economic crisis. Biden arrived in Chile late Thursday to attend the Summit of Progressive Leaders in the beach resort of Viña del Mar.

He will be joined by British Prime Minister Gordon Brown.

9-YEAR ABSENCE

The Summit of Progressive Leaders was a brainchild of Bill Clinton's, along with former British Prime Minister Tony Blair and former German Chancellor Gerhard Schroeder.

Clinton only attended one summit in 2000 before leaving office -- and Bush never attended -- so this will be the first time in nine years the U.S. government is represented. Chile's Michelle Bachelet, Brazil's Luiz Inácio Lula da Silva, Argentina's Cristina Fernández and Uruguay's Tabaré Vázquez are expected.

From there, Biden will visit the Chilean capital, Santiago, for bilateral talks with Bachelet before traveling to Costa Rica to see Costa Rican President Oscar Arias, Panamanian President Martín Torrijos, Guatemalan President Alvaro Colom, Salvadoran President Elías ''Tony'' Saca, Honduran Vice President Aristides Mejía and the Prime Minister of Belize, Dean Barrow.

`BEYOND MEXICO'

El Salvador's President-elect Mauricio Funes, of the leftist Farabundo Martí National Liberation Front, also is expected to attend.

Nicaragua's Daniel Ortega snubbed the meeting but will send his deputy foreign minister.

''Biden's trip is important, because it's the first opportunity for a senior official to go beyond Mexico,'' said Michael Shifter, vice president of the Inter-American Dialogue think tank in Washington. ``I don't think all this signals that Latin America will be high priority, but it shows Obama wants to have a good understanding of all the issues. Meeting with the southern cone and Central American leaders shows a regional approach.''

In Costa Rica, Biden is expected to discuss the upcoming Summit of the Americas, to be held in Trinidad and Tobago April 17-19.

LEFTISTS

Experts say it's no coincidence that Biden's visits are being held in moderate nations that have avoided the Washington-bashing that has become popular among other Latin American leaders such as Ortega, Venezuela's Hugo Chávez and Evo Morales of Bolivia.

After decades of mostly conservative governments in much of Latin America -- particularly Central America -- several leftist leaders have been voted into power. That pushed Costa Rica, long considered a center-left nation, to the right side of the political spectrum.

''They want to send a message to the region,'' said Kevin Casas, a senior fellow at the Brookings Institution and a former vice president under Costa Rican President Oscar Arias. ``The two countries that were chosen are renowned for being moderate, being committed to human development and being committed to democracy.''

Across the rest of Central America, economies depend heavily on cash sent from immigrants in the United States, and a drop in those remittances is likely to be a key topic on Biden's agenda.

It's unclear what role Cuba will play in the discussions, although it's expected to be a key issue in Trinidad, as more and more hemispheric leaders take trips to Havana. The message: Uncle Sam is the lone man out.

''They are all telling Obama: Cuba is part of this hemisphere,'' Deere said.

`IT'S A NICE TOUCH'

Despite the regional nature of the gathering, Mexico is the driving hemispheric issue, said Susan Kaufman Purcell, who runs the University of Miami's Center for Hemispheric Policy.

''Maybe they sent Biden because they wanted to balance it out after all this attention to Mexico -- make sure all the other governments did not feel left out,'' Kaufman Purcell said. ``It's a nice touch to add balance and scope.''

Miami Herald special correspondents Gideon Long in Chile and Leland Baxter-Neal in Costa Rica contributed to this report.