"Governments are at risk of throwing away a great chance to stop more than one billion people going hungry," they added.
A draft declaration already circulating ahead of the "Hunger Summit" is "just a rehash of old platitudes," said Francisco Sarmento, ActionAid’s food rights coordinator.
"It says hunger will be halved by 2015 but fails to commit any new resources to achieve this... Unfortunately the poor cannot eat promises," he said in a communique.
The UN Food and Agriculture Organisation is hosting the summit at its Rome headquarters next Monday through Wednesday.
Italian Prime Minister Silvio Berlusconi is the only head of government from the Group of Eight industrialised countries who is expected to attend the summit.
"Rich countries are failing to show enough interest and urgency," Oxfam spokesman Frederic Mousseau said in the statement.
"At the G8 in Italy this summer they pledged 20 billion dollars (13.5 billion euros) for agriculture over three years, so they believe they have done enough. They haven’t -- and the 20 billion dollars is a mirage," he said.
"Less than a quarter of this money is new. The UN itself says that 25-40 billion dollars in public spending is needed each year just to keep up progress towards achieving the first Millennium Development Goal to halve hunger by 2015," Mousseau said.
FAO Director-General Jacques Diouf, at a news conference on Wednesday, called for 44 billion dollars a year in official development assistance to be invested in agriculture.
Diouf called for "a worldwide 24-hour hunger strike on the eve of the summit in a symbolic show of solidarity with the one billion people who are hungry in the world" and said he would observe the fast on Saturday.
--------------------------------------------------------------------------------------------------------------------------------
Image: Alberto Pizzoli/AFP.