On the eve of a major conference on drug problems in the Western Hemisphere, Human Rights Watch said Tuesday that jailing people for personal drug use constitutes a human rights violation and called for abolishing criminal penalties.

“To deter harmful drug use, governments should rely instead on non-penal regulatory and public health policies,” the organization said in a statement released at a news conference in Guatemala, where the annual general assembly of the Organization of American States this week will focus on the drug policies of member governments. “Subjecting people to criminal sanctions for the personal use of drugs, or for possession of drugs for personal use, infringes on their autonomy and right to privacy.”

Secretary of State John F. Kerry is heading the U.S. delegation to the conference.

Drug cultivation, trafficking and use have always been a major subtext of relations between the United States and the rest of the hemisphere. Many Latin American countries have long resented the U.S. focus on drug-related law enforcement and security in their countries, which has often overshadowed what they see as more important trade and development issues.

While levels of drug use are far higher in the United States, much of the supply comes from Latin America, which has suffered the brunt of violence associated with production and trafficking to the U.S. market.

More than half of the U.S. public, according to recent opinion polls, favors decriminalizing marijuana use. Eighteen states and the District allow medical marijuana, and 13 of them have eliminated criminal penalties for possession of small amounts by non-medical users.

Argentina, Mexico, Chile, Brazil and Uruguay have considered or taken steps to limit prosecution for personal drug possession or use, although it remains a criminal offense in most countries.

In a speech during his visit to Mexico last month, President Obama said he favored a “comprehensive approach,” including law enforcement, education, prevention and treatment. But he said, “I honestly do not believe that legalizing drugs is the answer.”

Latin American leaders at last year’s Summit of the Americas decided to make drug policies the centerpiece of this year’s OAS assembly and ordered an extensive report, released last month, on all aspects of the drug issue, including the violence it has generated. Although it did not advocate a particular course, the report noted the huge financial and social costs of incarcerating users and described alternative strategies.

“No one here is defending any position, neither legalization, nor regulation, nor war at any cost,” Colombian President Juan Manuel Santos said in describing the report. Calling for “better solutions,” Santos said that “we all share a common destiny; where we sometimes differ is in how we reach it.”

A hemisphere-wide discussion of the issue, he said, is overdue.

In calling for decriminalization of drug use, Human Rights Watch said enforcement of drug laws has “increased the profitability of illicit drug markets. That has in turn fueled the growth and operations of groups . . . that commit atrocities, undermine public security, and weaken the rule of law.”