U.S. President Barack Obama is among dozens of heads of state who are in Colombia for the Summit of the Americas.
The 33 presidents and prime ministers from Canada, the U.S., Caribbean, and Latin America are meeting in the resort town of Cartagena.
President Obama is expected to use the summit as an opportunity to emphasize the importance of expanding economic and other ties across the region.
While the U.S. president remains personally popular throughout the region, he faces growing discontent from his counterparts over a number of issues, including Washington's decades-long fight against the illicit drug trade and Cuba's continued absence from the summit.
A growing number of leaders, including the summit's host, Colombian President Juan Manuel Santos, have called for decriminalizing drugs in order to reduce the demand fueling the violent drug cartels. Dan Restrepo, Mr. Obama's national security advisor for Latin America, says the president does not support decriminalization.
There is also an increasing demand for the U.S. to end its five-decade-long embargo on Cuba and allow it to rejoin the Organization of American States. Ecuadorian President Rafael Correa is boycotting the summit to protest Cuba's absence and others are warning it should be the last without the communist-run island's participation.
President Obama can also expect to be in the minority in his opposition to 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.
Some information for this report was provided by AP and Reuters.