KOBE, Japan - In the wake of an ocean wave that horrified an unready world, hundreds of U.N. conference delegates today got down to the business of finding ways to give man more of an edge in an age-old battle with the worst of nature.

"We must draw and act on every lesson we can," U.N. Secretary-General Kofi Annan told participants in the World Conference on Disaster Reduction, which opened with a moment of silence for more than 160,000 people killed in the Dec. 26 earthquake-tsunami that ravaged coasts across south Asia.

"The world looks to this conference to help make communities and nations more resilient in the face of natural disasters," Annan said in his videotaped message.

The first day's agenda for the five-day meeting focused on routes to resilience: by protecting such critical facilities as hospitals and power plants against damage; building earthquake-safe structures, and bolstering communications systems, among others.

The Japanese government announced it would refocus its foreign aid program to put more emphasis on disaster reduction. Prime Minister Junichiro Koizumi, addressing the conference, also said his government would offer tsunami-warning training to countries struck by the powerful, earthquake-spawned wave that sped across the Indian Ocean last month.

"It will be possible to save many lives in future Indian Ocean tsunamis if early warning mechanisms are rapidly developed," he said.

An immediate conference goal is to lay the foundation for an Indian Ocean alert network like the one on guard for tsunamis in the Pacific. UNESCO is presenting a blueprint for a system of deep-water buoys, tide gauges and a regional alert center that would cost $30 million and go into operation by mid-2006. Several sessions here will deal with the practicalities of the plan.

"Rarely has a tragedy made a conference so topical and timely as this one," Annan said.

His U.N. emergency coordinator, Jan Egeland, told reporters he hopes governments and U.N. agencies will make a "strong commitment" here to establish the Indian Ocean system. He also said he believed that over the next 10 years all vulnerable populations will be covered by advance warning systems.

It was "heartbreaking," he said, to see almost 3,000 people killed in Haiti by a hurricane last summer, when better-prepared countries, such as Cuba and the United States, suffered relatively few casualties.

He told the conference, however, that "technology is not a cure-all."

Beyond the "hardware," Egeland said, children should be educated to the risks of disasters; hospitals, clinics and schools should be viewed as safe havens and built to withstand quakes, cyclones and other disasters; and all disaster-prone countries should adopt "action plans" to deal with the threats.

The conference convened in Kobe 10 years after much of this Japanese port city was devastated in a great earthquake that killed 6,400 people. Japanese officials have cited this country's experience with natural disasters as an example for other nations.

"The most important factor in disaster reduction is to learn lessons from past disasters and to take measures in response," Japan's Emperor Akihito said at the opening session.

His government's minister for disaster management, Yoshitaka Murata, noted that tropical storms were once major killers here.

"In the devastated and vulnerable land after World War II, every major typhoon cost us thousands of lives," he said. "Japan has since reinforced the systems for disaster management and invested in disaster reduction."