George Clooney's humanitarian organization has donated $500,000 to a U.N. food aid agency to supply flights in Sudan's Darfur region, the agency said Thursday in Rome.

The Rome-based World Food Program said the donation came from Not On Our Watch. The group was founded by Clooney and other actors including Brad Pitt, Matt Damon and Don Cheadle to press concerns about Darfur.

The WFP warned earlier this week that a lack of funds would force an end to the flights ferrying urgently needed supplies to the violence-wracked region at the end of March.

Clooney's group has raised more than $9.3 million for Darfur.