The U.N. should start development of an early warning system in the Indian Ocean, nations affected by the Asian tsunami agreed on Thursday at a disaster prevention conference in Kobe. India, Thailand and Indonesia have all proposed establishing tsunami warning centers, however, experts say any warning system needs to be developed at an international level. With the neutral authority of the U.N. spearheading the project systematic participation will be best achieved, Hans Joachim Daerr, head of the German delegation, told Deutsche Presse-Agentur dpa. "Only an ocean-wide system makes sense," said Daerr. A basic system could be ready in 12 to 18 months, said U.N. agencies at the conference. A network of high-tech buoys anchored to the ocean floor and linked to a regional communications center will be needed. Millions of dollars have already been pledged by Japan and the European Union for the system and the U.S., Germany, Japan and Australia have already offered up their own technology for its development. The death toll from the December 26 earthquake and resulting tsunami has jumped to 226,000 after Indonesia declared 50,000 missing as dead.