ICAO is funded and directed by 193 national governments to support their diplomacy and cooperation in air transport as signatory states to the Chicago Convention (1944).
Its core function is to maintain an administrative and expert bureaucracy (the ICAO Secretariat) supporting these diplomatic interactions, and to research new air transport policy and standardization innovations as directed and endorsed by governments through the ICAO Assembly, or by the ICAO Council which the assembly elects. Industry and civil society groups, and other concerned regional and international organizations, also participate.
Once governments achieve diplomatic consensus around a new standard’s scope and details, it is then adopted by those same 193 countries in order to bring worldwide alignment to their national regulations, helping to realize safe, secure and sustainable air operations on a truly global basis.
ICAO is not a regulator. ICAO standards contain never supersede the primacy of national regulatory requirements. It is always the local, national regulations which are enforced in, and by, sovereign states, and which must be legally adhered to by air operators making use of applicable airspace and airports.
In addition to these core diplomatic and research capabilities, ICAO also conducts educational outreach, develops coalitions, and conducts auditing, training, and capacity building activities worldwide per the needs and priorities governments identify and formalize.