The UN agency said the additional people will be met by the International Committee of the Red Cross which aims to feed up to 320,000 people a month in Darfur.
"The Darfur conflict is now sadly half way through its third year. In May, WFP fed a record of 1.8 million people in Darfur, most of them stranded in camps after being forced from their homes and farms," said Ramiro Lopes da Silva, WFP's country director in Sudan in a statement.
"But large numbers of others can no longer provide for themselves because of insecurity, drought, the poor harvest last year and with local markets closed. They don't live in camps, but are all caught in the same Darfur trap, and urgently need our help to survive," he said.
The revised WFP operation foresees the number of internally displaced persons (IDPs) staying unchanged at 1.5 million in Darfur.
The UN food agency said insecurity, conflict and the poor harvest disrupted livelihoods, impeded traditional migration and trade routes and blocked the return of IDPs to their homes.