A debt relief program for the world's poorest countries is facing a $7.8 billion funding shortfall, mostly from the World Bank, a U.S. Congressional watchdog told lawmakers on Tuesday. And the gap may be even higher because data for Laos, Liberia, Somalia and Sudan are unreliable, the General Accounting Office said. "The three key (development banks) we analyzed face a funding shortfall of $7.8 billion," Thomas Melito, acting director of International Affairs and Trade at the GAO told a House of Representatives Financial Service Subcommittee.