Countries affected by the south Asian tsunami should have a warning system against sea surges in place by July, the UN's top humanitarian official promised Monday at the start of a UN conference here. The early alert system will not cover every community in the vast area that was devastated by killer waves on December 26, 2004, but should function on a national and regional level, UN Under Secretary Jan Egeland told reporters. "I think we will have a warning system operational from July. It does not mean every villager in every community will have a system to warn him or her, but we will have regional and national systems," he said. Egeland was speaking at the start of the Third Conference on Early Warning, a UN gathering designed to improve how alerts about natural disasters are sent out to authorities and the public.