Leaders of the Americas opened a two-day regional summit Saturday in Cartagena, Colombia, with discussions expected to include disagreements over Cuba and the failing war on drug trafficking.
More than 30 heads of state and government are taking part in the sixth Summit of the Americas, including U.S. President Barack Obama and host Colombian President Juan Manuel Santos.
Speaking at the opening ceremony, President Santos urged his fellow leaders to be "partners for prosperity," which is part of the official theme of the gathering.
Mr. Obama has said his goal in Colombia is to open new markets for American products. But other, more contentious issues appeared likely to dominate the discussions.
The United States is facing growing discontent over its continuing opposition to including Cuba in regional partnerships.
Ecuadorean President Rafael Correa is boycotting the summit to protest Cuba's absence, while other leaders have said this should be the last regional meeting to exclude the communist-run island.
Another divisive issue is drug legalization, which Colombian President Santos and other leaders say should be considered as a more effective and less expensive alternative to the U.S.-led war on drugs.
At a gathering of business leaders ahead of the summit, President Obama said it is entirely legitimate to debate whether drug laws already in place should be modified, but that "legalization is not the answer."
Appearing alongside Mr. Santos and Brazilian President Dilma Rousseff, Mr. Obama urged governments to strengthen their institutions and the rule of law, and acknowledged the need to reduce demand for illegal drugs in the U.S.
The United States is also in the minority at the Cartagena summit in opposing Argentina's claim to the British-controlled Falkland islands.
Washington's influence in Latin America has waned since the last summit in 2009, as the region increases its economic and diplomatic ties with emerging economies such as China and India.
At Saturday's CEO gathering, Mr. Obama spoke of impressive economic growth in Latin America and said the U.S. wants deeper economic partnerships in the hemisphere. But he said trade across the hemisphere is only half of what it could be and that "clean, transparent, open government" is needed to achieve further integration.
Venezuelan President Hugo Chavez, who has been battling cancer, is also absent from the summit. Venezuela's foreign minister, Nicolas Maduro, said Saturday that Mr. Chavez decided not to attend on the advice of his doctors. The Venezuelan leader was scheduled to travel to Cuba Saturday to continue radiation treatment.
Some information for this report was provided by AP, AFP and Reuters.