Brazil has temporarily banned rice exports to protect its domestic supply and contain pressure on food prices.

Brazil will not meet orders from other Latin American countries and Africa for half a million tonnes of the grain.

Rice is a staple food in the diet of many Latin American countries and in Brazil its wholesale cost has been rising by nearly 1 per cent every day over the past month.

Brazil grows more rice than it consumes but the Government says the export ban is necessary to ensure domestic supply for the next six to eight months.

With international prices at record levels, local producers are keen to export and are warning the Government against jeopardising foreign contracts.

Brazil's neighbour Argentina is also halting exports to contain local prices and just yesterday the Governments of Venezuela, Bolivia, Nicaragua and Cuba agreed on a $105 million plan to grow more food.

Japan has promised $US100 million in emergency aid to help countries struggling with rising food prices.

A Japanese Government spokesman says the first $US50 million will be distributed next month through the United Nations World Food Program, with most of it going to countries in Africa.

Japan has also pledged to put the food crisis on the agenda when it hosts the annual G8 summit in July.