The four countries, joined in a trading bloc called ALBA, said they would step up agricultural production efforts.
Critics say the Bush administration is relying too heavily on the military.
Tight supplies reflect population boom and neglect of farming.
Rich nations must act to ensure supply, experts say.
Opposition lawmakers have called for Prime Minister Jacques Edouard Alexis resignation in the wake of violent demonstrations over the rising price of food.
The rising prices complicate policy efforts to battle recession.