It was the first time Harper has suggested he is open to discussing new approaches to the war on drugs. Several Latin American countries, including Guatemala, Mexico and Colombia have called for an open and frank discussion about how to deal with the cartels.
"There is increasing doubt about whether we are taking the best approach to doing that, but nobody thinks these transnational networks are good guys, or that changing the law is somehow going to make them good people," Harper told reporters at a news conference following the close of the Summit of the Americas.
"I think what everyone believes and agrees with, and to be frank myself, is that the current approach is not working, but it is not clear what we should do."
The gathering of 31 leaders agreed to analyse the approach to the drug situation in a more formal way through the Organization of American States (OAS).
While some voices in Latin America and the Caribbean have suggested legalization and regulation of drugs might alleviate some of the suffering and violence in the region, others have opposed the idea.
But there is some consensus that countries such as Canada and the United States, who consume the lion's share of the drugs produced in the south, should be doing more to solve the problem.
El Salvador's president Mauricio Funes told the Latin American network NTN24 that the U.S. is not doing its fair share, and actually spent more money fighting leftist guerrillas during the country's civil war than it is in helping fight the cartels. More than 1,000 Salvadorans have died in drug-related violence in the past three months alone.
Harper announced funding related to that battle on Sunday.
A new Canadian Initiative for Security in Central America will spend $25 million over five years to help with the training of law enforcement agencies and the providing of police equipment.
Harper made it clear that he sees no easy solutions as to what to do next.
The Conservative government recently introduced stiffer penalties for Canadians who grow even small numbers of marijuana plants. He spoke of the wide penetration of drugs across Canadian society.
"There is a willingness to look at the various measures that can be taken to combat that phenomenon, but just in terms of simple answers like legalization or criminalization, let me remind you of why these drugs are illegal.
"They're illegal because they quickly and totally, with many of the drugs, destroy people's lives and people are willing to make lots of money out of selling those products ...," said Harper.
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