President Obama travels to a weekend summit of the hemisphere’s leaders Friday as the head of a nation that remains in many ways the economic envy of its closest neighbors, but also one whose influence is on the wane in a rising region.

At his first Summit of the Americas three years ago, Obama offered a different vision of American leadership in a region where, for decades, its economic policy and political preferences often left leaders and electorates angry at their powerful northern neighbor. Obama promised an equal partnership.

When he arrives in Cartagena, Colombia, where 33 of the hemisphere’s 35 leaders will gather for the summit, Obama will find himself on much more equal terms with his neighbors — for better or worse.

A Latin America more assertive politically and prosperous financially will be waiting for a president whose policies on immigration, the illicit drug trade and Cuba remain either at odds with the rest of the region or irritating to its people. Many are planning to let him know.

As the United States struggles to regain its economic footing, Latin America’s leaders have moved on from the largely U.S.-centric view of the world that followed the collapse of the Soviet Union. Some of the most influential have embraced policies that welcome China, India and Iran as economic and political partners.

Colombian Silvio Carrasquilla — a fan of President Obama — shows his Obama collection in his home in Turbaco, Colombia on April 12. Obama will attend the VI Summit of the Americas, being held in Colombia's Caribbean resort city of Cartagena. (Luis Acosta/AFP/Getty Images)

“This summit is hugely different from the first Summit of the Americas in terms of the United States and the hemisphere.,” said Cynthia J. Arnson, director of the Latin American program at the Woodrow Wilson International Center for Scholars. “Latin America has clearly emerged on its own.”

Obama, too, has focused on other parts of the world.

His immediate foreign policy priorities have been unwinding America’s wars, managing the unpredictable Arab Spring and shifting the country’s military, diplomatic and economic center of gravity toward Asia — leaving his backyard neighbors largely alone to forge their own way forward.

His advisers say he intends to emphasize trade, alternative energy development and other areas of economic cooperation during the summit — assets in an election year when the economy occupies center stage — while hearing out his Latin American and Caribbean counterparts on drug-trade violence, immigration and other issues where U.S. policy is not consistent with their own.

Opinion polls show that in some of Latin America’s most influential countries’ public perceptions of the United States have improved since Obama took office. And Latin American experts in Washington say that although the region’s love-hate relationship with the United States remains intact, Obama is personally popular in many of the countries.

“We really see the Americas as a success story, both in their own right and in terms of U.S. engagement,” said Ben Rhodes, Obama’s deputy national security adviser for strategic communications, in briefing reporters this week on the trip.

“On the economic side we see the Americas as fundamental to our export-driven strategy for economic growth,” Rhodes said.

Obama will stop in Tampa on his way to Cartagena on Friday, to deliver a speech at the city’s port on the importance of trade with the Americas, the market for 40 percent of U.S. exports.

“As countries in Latin America become more prosperous and more people move out of poverty, that creates opportunity for us as well,” Rhodes said.

At the last summit in Trinidad and Tobago in 2009, Obama, just months in office, had to explain a severe regional economic downturn that, unlike several recent ones, was not made in Latin America.

Some of the region’s most enterprising countries have endured the global economic slowdown much better than their rich northern neighbor. The contrast has given the region’s leaders and business executives a new confidence that, although the United States remains a key market for their goods, it is not necessarily the policy guide it once purported to be.

“The quality and intensity of ties have diminished,” wrote Michael Shifter, president of the Washington-based Inter-American Dialogue, in a report released this week. “Most countries of the region view the United States as less and less relevant to their needs — and with declining capacity to propose and carry out strategies to deal with the issues that most concern them.”

Latin America’s resilience, along with U.S.’s ailments, has prompted leaders in some nations to look farther afield for economic and political allies.

China’s share of trade in Brazil, Chile and Peru has passed that of the United States, according to the Inter-American Dialogue report. It is a close second in Argentina and Colombia, where a free-trade agreement with the United States is now being implemented.

At the same time, U.S. exports to the region have more than doubled since 2000, evidence of Latin America’s rising middle class. Brazil has become the prime example of the region’s confidence and stature.

Along with its expanding economic clout, Brazil is increasingly assertive on the world stage, seeking, for example, a permanent seat on an expanded U.N. Security Council that Obama has endorsed in principle. Brazil is aligned closely with India, Russia and China in a powerful developing-world bloc, and the Obama administration views it as a key, innovative partner in the development of alternative energy.

After an Oval Office meeting with Brazilian President Dilma Rousseff this week, Obama called the country “not only a leading voice in the region, but also a leading voice in the world.”

Brazil’s leaders were pleased when Congress allowed an onerous tariff on ethanol imports to lapse last year, but Rousseff, in her appearance with Obama, still criticized what she called the “expansionist monetary policies” of the United States. She complained that they were devaluing the currencies of emerging countries in Latin America and beyond.

Although the Federal Reserve is responsible for U.S. monetary policy, not Obama, Rousseff’s willingness to criticize the president reflected Brazil’s heightened sense of itself on the world stage.

“I think managing disagreement is now the way forward,” said Julia E. Sweig, director for Latin American studies at the Council on Foreign Relations.

“How do two giant continent-size countries in the Americas relate to each other?” Sweig asked. “I see this as early days, and I actually believe there’s a great deal of thinking behind the diplomacy between the two countries on how to connect on science, climate change and in other areas.”

U.S. election-year politics might constrain Obama from making promises at the summit on immigration reform, environmental policy and lifting the decades-old embargo on Cuba, whose leader, Raul Castro, was not invited to attend the summit, much to the consternation of regional leaders. Ecuador’s president Rafael Correa declined to attend in protest, and Rousseff has indicated that this summit might be the last that Brazil attends without Cuba’s participation.

Administration officials are also preparing to be challenged on U.S. drug policy, as American demand continues to drive an illicit trade that is spawning devastating violence in several weakly governed Central American countries, Mexico, and several other Latin American and Caribbean nations.

More and more Latin American leaders, including the summit’s host, Colombian President Juan Manuel Santos, are raising the possibility of legalizing the drug trade in a tacit declaration that the U.S.-funded policies that make up the “war on drugs” have not worked.

“The president doesn’t support decriminalization,” said Dan Restrepo, the National Security Council’s senior director for the Western Hemisphere, in briefing reporters this week. “He does think this is a legitimate debate, and it’s a debate that we welcome having because it helps demystify this as an option.”

The region’s leadership is also changing, leaving a political vacuum in some ways and no obvious partner for Obama.

Colombia’s then-President Alvaro Uribe played that role for Obama’s predecessor, George W. Bush, but Santos has shown a willingness to turn away from Uribe’s policies and his unconditional alliance with the United States.

The Castros are growing old in Cuba, Venezuela’s populist firebrand Hugo Chavez is battling cancer and faces an election this year, and Mexico’s Felipe Calderon also will be departing soon because of his country’s one-term limit. Obama, consumed by domestic issues and his own election prospects, will be challenged to find his own place in a region where the United States casts a smaller shadow than it once did.

“I think they are quite comfortable with the diminished role in the hemisphere, and I think it is coming from President Obama himself,” said Andrew Selee, director of the Mexico Institute at the Woodrow Wilson International Center for Scholars. “He comes to this recognizing that U.S. power has diminished in the hemisphere — and that that is the natural order of things.”