ICAO is the international Civil Aviation Organization:
An agency of the United Nations which deals with problems of international civil aviation and sets standards and regulations. it is responsible for coordinating and regulating international air travel.
In the context of travel and transport, ICAO plays a key role in setting standards and policies that govern the operation of international air transportation. This includes establishing safety standards for aircraft and airports, developing regulations for the operation of airlines, and promoting cooperation among countries in order to facilitate the smooth operation of international air travel.
ICAO works closely with other organizations and agencies that are involved in the travel and transportation industries, such as the International Air Transport Association (IATA), the Federal Aviation Administration (FAA), and the European Union Aviation Safety Agency (EASA). It also works with governments and airlines around the world to promote the safe and efficient operation of international air travel.