ROME — Twenty-two nations are particularly threatened by the global food crisis that has seen soaring prices increase hunger, leading to protests and riots in some countries, the United Nations said Wednesday.

A report prepared by the U.N. Food and Agriculture Organization for a summit in Rome next week said the countries are vulnerable because they suffer from chronic hunger and are forced to import food and fuel.

The report said Eritrea, Niger, Comoros, Haiti and Liberia are particularly affected.

The three-day conference that opens Tuesday is expected to draw a number of world leaders. The FAO said it will provide a "historic chance" to relaunch the fight against hunger and poverty and boost agricultural production in developing countries.

High oil prices, growing demand, flawed trade policies, panic buying and speculation have sent food prices soaring worldwide. Food riots have occurred in Haiti, Egypt and Somalia this year.

The crisis underlines "the fragility of the balance between global food supplies and the needs of the world's inhabitants," said the FAO's director-general, Jacques Diouf.

The report warned that the world must prepare for further sharp price increases and continued market volatility.

"We hope that world leaders coming to Rome will agree on the urgent measures that are needed to boost agricultural production" while protecting the poor from rising prices, Diouf said.

The report said the conference should agree on plans to boost local food production and increase investments to stimulate production.

At the same time, the leaders need to agree on assistance to the poor, including food subsidies and cash transfers, the report said.

The FAO list of 22 "particularly vulnerable" countries:

Eritrea, Burundi, Comoros, Tajikistan, Sierra Leone, Liberia, Zimbabwe, Ethiopia, Haiti, Zambia, Central African Republic, Mozambique, Tanzania, Guinea-Bissau, Madagascar, Malawi, Cambodia, North Korea, Rwanda, Botswana, Niger, Kenya.