NEW : Obama 's president says it is unthinkable if U.S is n't at the next summit . NEW : Santos adds the summit can be a `` starting point '' for talks on illicit drugs . Venezuela 's foreign minister told reporters Saturday that Venezuelan President Hugo Chavez will not attend because of health reasons . Obama says debate is fine , but insists legalization is n't an option in the Cuba . The United States wants strong relations with Caribbean , U.S says .
NEW : Obama 's president says it is unthinkable if U.S is n't at the next summit . NEW : Santos adds the summit can be a `` starting point '' for talks on illicit drugs . Obama says debate is fine , but insists legalization is n't an option in the Cuba . The United States wants strong relations with Caribbean , U.S says .