The twin crises — in the cost of food and in global financial markets — have prompted an appeal for $1.5 billion to ward off a looming humanitarian catastrophe in the world's poorest regions.

UNICEF will today release its annual snapshot of the plight of people in disaster zones, calling for urgent action in 36 countries.

Australia's neighbourhood is not immune, with Burma and East Timor counted among the most needy.

The Humanitarian Action Report says the devastation caused by cyclone Nargis in Burma last May has meant about 20,000 children still suffer food shortages.

In East Timor, nearly half of children under five are underweight.

Carolyn Hardy, head of UNICEF Australia, said the downturn in the global economy had made rich countries focus on economic troubles at home.

"I think we're all feeling the effects of the global financial crisis — job loses, profit downgrades, budget deficits, etc," she said.

But, Ms Hardy said, the global food crisis had not gone away in poor countries, despite the steady drop in oil prices in recent months contributing to the lowering of production and transport costs.

"I don't think it (the food crisis) has been forgotten, but there are far more domestic priorities for a lot of donor governments. We hope that this report will put it back on the agenda for them," she said.

A two-day summit was scheduled to begin in Madrid overnight, with UN Secretary-General Ban Ki-moon as chairman.

It will bring together the leading emergency food agencies in search of ways to end the shortages.

World leaders pledged last June to alleviate the suffering caused by rising food prices and stimulate agricultural development.

But since then the value of financial markets has crashed and big industrial economies have slipped into recession.

The UNICEF appeal is to meet the needs of an estimated 950 million people going hungry, an increase of 17pc since last year.

Last year's fuel price rises, poor farming methods and climate change are each said to have contributed to a sharp increase in the cost of staples such as rice and wheat.

"It's not just that what we needed to do last year is being repeated; this year there is an increase in it," Ms Hardy said.

"I think we're all concerned that it's going to be very difficult to fund that given the global financial crisis."

The Australian Government has promised to boost total spending on foreign aid by the middle of the next decade to 0.5pc of gross national income.