It will be consigned to the United Nations World Food Program (WFP) and will provide for the essential food needs of 300,000 people for four months.
"Our food donation will support the government of Sri Lanka’s commitment to return displaced citizens to their homes quickly and safely," USAID Mission Director Rebecca Cohn said.
"As part of this support, our food will be used for the six-month ration that people receive once they return to their homes.
"In addition, our food may be used for short-term, food-for-work activities to help the most vulnerable of these people restart their livelihoods."
The food aid is meant to feed refugees once they are resettled.
Thousands of civilians were made refugees by the fighting between government forces and Tamil Tiger rebels.
The 30-year ethnic war