U.S. President Barack Obama is calling for more cooperation among the nations of the Western Hemisphere to assure economic growth and make certain that globalization benefits all levels of society.

On a separate issue expected to come up at this weekend's Summit of the Americas, a two-day meeting in Colombia of 33 heads of state or government, Mr. Obama said the United States continues to oppose legalization of narcotics. The summit host, Colombian President Juan Manuel Santos, and several other leaders say legalization should be considered as an alternative to the expensive and ineffective U.S.-led war on drugs.

Addressing corporate leaders at a separate meeting in the resort city of Cartagena, Mr. Obama said the days are “long gone” when nations could develop economic policy in isolation from regional partners. The government leaders' summit talks are beginning later Saturday .

Appearing alongside Brazilian President Dilma Rousseff and Mr. Santos, Mr. Obama said Western Hemisphere countries are very well-positioned in the global economy, but still face the challenge of ensuring that globalization and integration benefit a broad base of people, and that economic growth is sustainable.

President Obama is expected to use the summit as an opportunity to emphasize the importance of expanding economic and other ties across the region.

Mr. Obama's personal popularity is strong throughout the Americas, but he is likely to hear growing discontent at the summit over a number of issues, including the effort to control the drug trade and Washington's continuing refusal to include Cuba in regional partnerships.

The Colombian president says decriminalizing drugs would the power that violent drug cartels exert in his nation.

President Obama said Saturday that it is entirely legitimate to debate whether drug laws already in place should be modified, but that “legalization is not the answer.” He urged all 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 U.S. embargo on communist Cuba, in effect for the past five decades also is unpopular in many parts of Latin America, and there have been increasing calls to allow Havana to rejoin the Organization of American States. Ecuadorian President Rafael Correa is boycotting the summit to protest Cuba's absence, and other leaders have said this should be the last regional meeting to exclude the communist-run island. Venezuela's ailing president, Hugo Chavez, also is not attending the meetings.

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.