America’s Central Intelligence Agency (CIA) list maintains a list of Heads of State and cabinet level officials for most countries in the world.  These people are likely to be considered politically exposed, and should be included in any PEP screening that a client has. 

The directory is intended to be used primarily as a reference aid and includes as many governments of the world as is considered practical, some of them not officially recognized by the United States. 

The list is publicly available (https://www.cia.gov/library/publications/world-leaders-1/) however most organisations will consume this data as part of a larger screening programme, which normally consumes this list, other sanctions list and Politically Exposed Person (PEP) lists to ensure that data is consumed in the most efficient method.