Summary: GAO: (1) reviewed the structures and certain operational aspects of the United Nation's (U.N.) internal and external audit and evaluation units; and (2) examined whether a central authority might improve the effectiveness of the current U.N. system of audit and evaluation. GAO noted that: (1) the current U.N. internal and external audit and evaluation structures do not ensure program accountability or provide member states with adequate oversight of U.N. finances and operations; (2) U.N. lacks a common set of accounting principles and standards; (3) if the existing internal and external audit and evaluation structures were centralized under an independent, central audit and evaluation authority, U.N. could resolve many of these problems; (4) by consolidating the current fragmented resources, U.N. would be able to more efficiently direct resources for more effective audit and evaluation coverage of its programs and operations; and (5) the role of the Board of Auditors should be changed from one of actually conducting the audits to one of overseeing the activities of an audit and evaluation authority on behalf of the General Assembly.