The World Health Organization declared swine flu as the first international pandemic of the century on Thursday and urged nations to step up the fight against the virus.

The World Health Organization's Director-General Margaret Chan announced that the organization decided to raise its alert against the swine influenza A-H1N1 virus to Phase 6 - the highest level - following a meeting of health experts in Geneva. This is the first time a pandemic has been declared since 1968.

What is a Pandemic?
The announcement, Chan said, means that countries must keep a close watch on the virus. She called the situation a moderate pandemic.

"Calling a pandemic is also a signal to the international community," said Chan. "This is a time when the world's countries - rich or poor, big or small - must come together in the name of global solidarity to make sure that no countries because of poor resources, no country's people should be left behind without help."

The World Health Organization says that, so far, 74 countries have reported nearly 30,000 cases of flu, with 144 deaths.

The WHO is urging drug makers to speed up the manufacture of a swine flu vaccine. But Chan said it is also important that drug makers keep their timetable to finish producing this year's seasonal flu virus vaccine. Normal influenza usually kills about a half a million people each year.