Jamal al-Fadil Faraq Allah, a Sudanese driver for a staff member with the U.N. World Food Program, was killed by unknown assailants in the Sudanese state of South Kordofan.
"It is unacceptable for humanitarian workers to face attacks while they are working on the front-lines of hunger in countries like Sudan," WFP Executive Director Ertharin Cousin said in a statement.
WFP last week said it was "pulling out all the stops" in Sudan by airdropping more than 2,000 tons of food in parts of the country.
The incident coincided with a visit by U.S. Secretary of State Hillary Clinton to the region. The United States helped broker the 2005 peace deal that secured South Sudan's independence last year. Ethnic violence and border skirmishes have threatened to derail the fragile peace.
The African Union, however, managed to secure good-will gestures from both parties to the conflict during the latest round of multilateral negotiations held in Ethiopia.
Clinton, in a statement, said Sudan could secure "a brighter future" if it took steps to bring peace to South Kordofan and other border states.
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