A deadly swine flu virus strain could unleash a new global pandemic, UN Secretary-General Ban Ki-moon warned Monday, after the probable death toll from the disease rose to 149 in Mexico.
"We are concerned that this virus could cause a new influenza pandemic. It could be mild in its effect or potentially be severe," Ban told reporters.
"We don't know yet which way it will go but we are concerned that in Mexico most of those who died were young and healthy adults."
Ban described the outbreak as the "first test" of the pandemic preparedness work undertaken by the international community over the past three years.
The United Nations is responding "quickly and effectively," he said, adding that the World Health Organization (WHO) was leading the global body's efforts to tackle the outbreak.
The emergency committee convened by WHO chief Margaret Chan was set to meet again late Monday to decide whether to raise its pandemic level from the current level three to four, which signals a "significant increase in risk of a pandemic."
Phase three indicates that an animal or human-animal flu virus has caused sporadic cases or small outbreaks in humans, but has not resulted in human-to-human transmission that is sufficient to sustain community-level outbreaks.
"If we are indeed facing a pandemic, we need to demonstrate global solidarity," said Ban. "In our interconnected world, no nation can deal with threats of such dimension on its own."
He stressed that poor nations were "especially vulnerable."