The international aid group, Care, has rejected a donation of $45m (£22.7m) from the United States government.
Care said it did not oppose emergency food aid during a crisis
Care criticised the way US food aid is distributed, saying it harms local farmers, especially in Africa.
It said wheat donated by the US government and distributed by charities introduced low prices that local farmers are unable to compete with.
But USAid says assessments are carried out to try to ensure that commodities do not disrupt local production.
Correspondents says disagreements have emerged in the US aid community on the best way to use food aid.
"We came to the realisation that if we wanted to do what was in the best interest of poor people and efficiency in aid, that this wasn't it," Care President Helene Gayle told Reuters news agency.
Care said it did not oppose emergency food aid during periods of drought or famine.
But the group said the US government's method of food aid did not help communities which were permanently in need.