UNITED NATIONS - The head of the United Nations World Food Program appealed to goverments Friday to provide more cargo aircraft and helicopters to deliver relief supplies to victims of the tsunami disaster but praised the world's generosity in aid so far.

WFP Executive Director James Morris' comments came as the United States announced it was increasing its pledge tenfold to $350 million - and his statement contrasted with an earlier U.N. official's criticisms that rich countries are in general "stingy" in giving help to developing nations.

"At the end of the year with a series of crises unfolding, with a cumulative effect that stretched donor resources to the limits, it is extremely gratifying to see such a swift and generous response to this new catastrophe, perhaps the worst natural disaster in history," Morris said.

He stressed that the victims would need "massive international aid" for many months to come.

Hundreds of millions of dollars have been pledged from governments around the world to help millions of people affected by Sunday's disaster, which killed more than 121,000.

At a meeting Friday with officials from the United States, Japan, Australia and India, Morris appealed for cargo aircraft and helicopters.

"We have a critical need for airplanes and helicopters given the wide geographic expanse and difficult terrain. We would be very grateful if countries were able to urgently help us meet our air transport needs," he said.

In Sri Lanka, where the WFP has 5,000 tons of food stocks, rice, wheat flour, lentils and sugar, convoys of trucks have been heading for the worst hit parts of the country. The WFP said it expects to provide 750,000 people with enough food for two weeks by January 6th. The agency is also airlifting food to Indonesia's Aceh province and sending food overland to Somalia.