The United Nations chief told a news conference at his organisation's summit on the food crisis that most of that money 'will come from concerned countries themselves'.

But he said that contributions will also be needed from the World Bank, the International Monetary Fund, the World Trade Organisation and development banks.

'Perhaps as much as US$15 billion to US$20 billion' will be needed annually, he said.

On Tuesday, Mr Ban warned of the prospect of nearly a billion people going hungry if the world does not act immediately to resolve the crisis, and called for a 50 per cent increase in food production by 2030.

And yesterday, he stressed: 'We must make the international trade system work more effectively to make more food available, at reasonable prices.'

He also said harvests must be increased next year through the urgent supply of seeds and fertiliser.

The three-day summit, which ends today at the UN Food and Agriculture Organisation headquarters in Rome, is trying to find short-term solutions to the food price crisis as well as a more lasting strategy to deal with causes.

World Bank president Robert Zoellick told reporters that there has been 'considerable consensus' at the summit on the causes of the crisis and how they should be handled.

He did not say what might come out of a final document being worked on.

But Mr John Holmes, a top UN humanitarian affairs official leading a food crisis taskforce, sounded an optimistic note about the prospects of finding a workable solution.

'This is not rocket science,' he said. 'We know what to do. Now, we just need to do it.'

One sticking point, however, would appear to be the controversial issue of biofuel production, on which Mr Ban said 'policy guidelines' were needed.

Making fuel from corn, sugar and other organic material uses food that could feed people or animals.

Environmentalists, international groups and some countries are becoming increasingly wary of biofuels, which they say could accelerate global warming by encouraging deforestation as well as contributing heavily to the commodities price hike by diverting production from food crops.

But on the other side of the debate are countries such as Brazil, whose sugar cane has long been used to produce ethanol fuel.

Brazilian President Luiz Inacio Lula da Silva said on Tuesday: 'It is frightening to see attempts to draw a cause-and-effect relationship between biofuels and the rise of food prices.

'It offends me to see fingers pointed against clean energy from biofuels, fingers soiled with oil and coal.'

The United States has also been heavily subsidising corn-based ethanol production, and US Agriculture Secretary Ed Schafer said yesterday that he foresaw trouble with the wording of the summit's final declaration.

'I doubt there will be a positive agreement on biofuels,' he said.

ASSOCIATED PRESS