The Red Cross and other disaster relief charities aren't prepared to meet projected mass casualty needs from a major disaster in such cities as Washington, New York, Los Angeles and Miami, the nonpartisan Government Accountability Office said in a study released Thursday.

The non-profit organizations have federal responsibilities for assisting the government in feeding and sheltering victims.

The report further criticized the Federal Emergency Management Agency for not clearly explaining the roles each should play in a disaster, The Washington Post reported.

While spending about $80 million upgrading its equipment, the Red Cross, the nation's largest disaster relief organization, plunged into debt to provide aid after Hurricanes Gustav and Ike.

In an unusual step, it asked the U.S. Congress for $150 million in emergency funding.