World Health Organization (WHO) chief Margaret Chan warned Monday that the current swine flu pandemic could cripple fragile health services in poor countries.
"Developing countries have the greatest vulnerability and the least resilience. They will be hit the hardest and take the longest to recover," she told a UN forum on global health.
Last week, WHO raised its global alert to a maximum six, saying swine flu had reached pandemic status because of its geographical spread.
The virus, which was first detected in Mexico in April, has so far infected almost 30,000 people in 74 countries, according to the latest WHO figures. Around 150 of those have died.
"The pressures of a pandemic, on top of the rise in chronic diseases, could alone cripple fragile health services" in the developing world, Chan said.
While noting that the world's preparedness for the pandemic was unprecedented, she stressed that "the level of preparedness, and the capacity to cope, are strongly biased toward wealthy countries."
"In terms of measures to mitigate the health impact, many poor countries are virtually empty-handed," the WHO director general said. "Even the use of non-pharmaceutical measures has limited relevance to poor countries, especially in sub-Saharan Africa."
She added that "greater equity in the health status of populations, within and between countries should be regarded as a key measure of how we, as a civilized society, are making progress."
Meanwhile UN chief Ban Ki-moon told the same forum that the world should put a greater focus on improving maternal health.
"I am most troubled by the costs of failed maternal and child health. The global impact of maternal and newborn deaths has been estimated at 15 billion dollars a year in lost productivity," he noted.
"We must use maternal health as a lens through which we decide and act on global health policies,"Ban said. "The international community should apply its valuable experience of fighting AIDS and malaria to saving mothers' lives."