NEW YORK -- A UN rights advocate said that millions more of the world's poor suffered malnutrition last year.

The advocated also charged that the trade practices of wealthy nations and desert encroachment aggravated the problem.

Jean Ziegler, a UN expert on food rights, said that some 852 million people were "gravely, permanently undernourished on this planet" at the end of 2005, an increase of 11 million from the year earlier.

Much of that increase came in Africa, where drought, climate change and poor farming practices are spreading the Sahara Desert further southward into once-fertile lands, Ziegler told a news conference.

He also said that unfair trade practices by rich nations hurt food production in Africa, where excess food from rich nations can be dumped in local markets, undercutting local producers.

Africa is seeing hunger increases in both absolute and relative terms, meaning the rate of increase of hungry people is greater than the overall increase in the population, he said.

Still, "only the absolute figures are important, because these are human beings," said Ziegler. "They are living people who die from hunger.''

Ziegler, a university professor and former politician representing Switzerland's socialist party, said solutions to end hunger exist - but not the political will.

Fast-growing trees can be planted to secure fertile lands against encroaching Saharan sands, irrigation canals can be built to help farmers and pesticides can be employed early to kill crop-ruining insects, like the locusts that ruined farms two years ago in many West African countries, he said.