"This is one of the biggest challenges of our time and age, we need to make vulnerable people living in developing nations more resilient to natural hazards," Egeland told journalists during a meeting of a task force on disaster prevention.

Slack or non-existent prevention or mitigation efforts were a major problem, he added.

About 95 percent of deaths caused by natural disasters occur in developing countries, according to the United Nations, while losses as a proportion of national income were 20 times greater than in wealthy nations.

The task force highlighted the threat to "megacities" housing millions of people each in the developing world, if multi-storey housing was not adequately quake-proofed.

"We have seen 2004 and 2005 as the years of disaster," Egeland said, citing the earthquake in Pakistan, the Indian Ocean tsunami and hurricanes in the Caribbean.

"It's like nature strikes back on people who have treated nature badly and we see hundreds of thousands dead after these last two years and hundreds of millions of livelihoods lost."

"These people did not need to lose their lives," he added.

Egeland reiterated that quake-proof schools and hospital buildings in Pakistan, early warning systems in the Indian Ocean -- which are now being set up -- and better levees in New Orleans would have saved lives and livelihoods.

"I hope we will learn from these experiences and relaunch a more effective humanitarian system of effective prevention and preparedness," the UN relief chief added.

The UN wants 10 percent of humanitarian aid to be invested in disaster prevention measures.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.