The United Nations' top refugee official said on Thursday an international peacekeeping force in Darfur was essential to prevent the whole of central Africa descending into conflict, Reuters reported. U.N. High Commissioner for Refugees Antonio Guterres, in Chad on a two-day visit, said the international community faced a titanic task in moving some 230,000 Darfur refugees away from the country's violent border area with Sudan. "If the security situation deteriorates, we will have a very serious problem," the former Portuguese prime minister told a news conference. "That is why a solution to the Darfur problem is necessary for the stability of the whole region." Guterres' visit came as outgoing U.N. Secretary General Kofi Annan has launched a last-ditch effort for a "hybrid" peacekeeping force in Darfur consisting of African Union troops with substantial U.N. resources.