The White House announcement of President Barack Obama’s agenda for the upcoming April 10-11 Summit of the Americas in Panama, stating that he will meet with Caribbean and Central American leaders, raises a big question: Has the United States given up on South America?

According to a White House statement, Obama will travel to Jamaica on April 8 to meet with leaders from the 15-country Caribbean Community and hold a bilateral meeting with Jamaican Prime Minister Portia Simpson Miller.

From there, Obama will go to Panama to attend the 35-country Summit of the Americas, which for the first time will include Cuba. At the summit, Obama is scheduled to meet with leaders from the eight-country Central American Integration System, and with Panama’s President Juan Carlos Varela.

But what about Brazil and other South American nations that make up the bulk of Latin America’s economy? I asked U.S. officials in recent days.

So far, no group or individual meetings with South American countries are planned, officials say. They add that Obama will most likely meet informally with leaders of some South American countries at a private retreat with all participating heads of state during the two-day summit.

By comparison, Obama had a formal meeting with leaders from the 12-country Union of South American Nations (UNASUR) at the 2009 Summit of the Americas in Trinidad and Tobago. At the 2012 Summit of the Americas in Cartagena, Colombia — yes, the one mostly remembered for the U.S. Secret Service agents’ escapade with prostitutes — Obama met with Colombian President Juan Manuel Santos.

South America’s ties with the United States have deteriorated badly over the past decade, as China became the leading buyer of the region’s exports, and Brazil, Venezuela and other leftist-ruled countries — emboldened by their booming commodity exports — created their own sub-regional organizations such as UNASUR to exclude the United States from regional decisions.

UNASUR’s headquarters was placed in Ecuador, whose populist president, Rafael Correa, is a rabid U.S. critic. UNASUR is presided over by former Colombian President Ernesto Samper, whose U.S. entry visa was revoked in 1996 following charges that his 1994 presidential campaign had been funded by the Cali drug cartel.

Earlier this month, U.S-South American ties took a turn for the worse after Obama issued an executive order denying U.S. entry visas and freezing financial assets of seven Venezuelan government figures involved in human rights abuses, and UNASUR denounced the U.S. measure as an “interventionist threat” to Venezuela’s national sovereignty.

Michael Shifter, head of the Washington, D.C.-based Inter-American Dialogue think tank, says the absence of an Obama-UNASUR meeting at the upcoming summit in Panama “is a recognition of reality.” He added, “Reality is that the U.S. influence in South America has become marginal, and that if the United States has any influence in Latin America, it’s in Central America and the Caribbean.”

By focusing on Caribbean and Central American countries, Obama may be also trying to fill the vacuum left by financially bankrupt Venezuela in the Caribbean Basin. “Venezuela can’t maintain its support for Petrocaribe,” Shifter said, referring to the Venezuela-created institution that channels subsidized oil to Caribbean Basin nations.

U.S. officials reject the idea that the Obama administration has given up on South America, stressing that Caribbean Basin countries are facing some of the region’s worse violence, drug and energy problems. At the summit, Obama will try to enlist South American nations in efforts to help them, they say.

My opinion: Obama should reach out to Brazil and other South American countries at the summit.

Granted, his recent sanctions against the seven Venezuelan officials will be a problem, because Venezuela will ask its South American neighbors at the meeting to denounce what it calls U.S. “aggression.”

But times have changed, and for the first time in more than a decade it is in the interest of most South American countries to move closer to Washington.

South America’s commodity export boom is over, Brazil’s economy is expected to have its worst performance of the past 25 years this year, and both Argentina and Venezuela’s economies are hurting badly.

Meanwhile, China — a major engine of South America’s economic growth — is slowing down, and Europe is not seeing the light at the end of the tunnel. The United States is the only major world economy that is doing relatively well.

It’s a new regional scene. Obama should keep this in mind, and try to reset ties with South America — especially with financially ailing Brazil — at the summit.