The United Nations will launch an appeal for at least US$50 million (¤42 million) to improve animal surveillance in the fight against bird flu, an official said Monday. The appeal was needed following the spread of the deadly H5N1 strain outside southeast Asia and would be launched later this week, said Joseph Domenech, chief veterinary officer at the U.N. Food and Agriculture Organization. The money was necessary to strengthen the agency's capacity to detect the virus and the ability to provide an effective emergency response, Domenech was quoted as saying by The Associated Press. The Rome-based FAO calculated the appeal to cover response over 18 months in the Middle East, Eastern Europe and the Caucasus, Central Asia, and several regions in Africa, he said.