MEXICO CITY, July 7 (Reuters) - A spate of violence in Haiti could hinder the Caribbean country"s response to the coronavirus pandemic, the Pan American Health Organization (PAHO) said on Wednesday, shortly after Haiti"s president was assassinated in his home. COVID-19 cases in Haiti have declined but vaccinations have yet to begin for the country"s 11 million people, PAHO director Carissa Etienne said at a weekly briefing. Haitian President Jovenel Moise was shot dead by gunmen overnight on Wednesday, sparking fears of a descent into chaos in the impoverished country after months of escalating gang violence. "We continue to be concerned about Haiti," said Etienne. "The situation is still very difficult, with episodes of violence challenging the response to the pandemic." She added that PAHO would "redouble" efforts to help Haiti begin inoculations and prevent the spread of the coronavirus. "I am hopeful that the imminent arrival of vaccines in the country can start to turn the tide of the pandemic and bring some relief to the Haitian people during these very difficult times," Etienne said. The Americas account for more than half of the world"s COVID-19 deaths. Etienne strongly urged vaccine donations for struggling countries, with PAHO flagging that the COVAX vaccine-sharing facility faced serious supply-side problems last month, partly because of a vaccine shortage from India. PAHO warned that infections are increasing in Belize, El Salvador, Honduras, Panama, parts of Guatemala and certain areas of Mexico, including the sprawling capital of Mexico City. The 1.1 million new coronavirus cases reported in the Americas last week represented a slight decline from the earlier week. Etienne added that community transmission of the highly contagious Delta variant continues to be limited in Latin America, and is mostly associated with travel.