In several Latin American countries, a cadena nacional (Spanish for 'national network'; plural cadenas nacionales), also referred to as a cadena oficial (Spanish for 'official network') or red voluntaria (Spanish for 'voluntary network'), is a joint broadcast, over various media (usually radio and television), directed at the general population of a state. Initially conceived as a form of emergency population warning, these broadcasts are often of a political nature, as most of them are messages by governmental authorities about various topics of general interest.
Depending on the country, the characteristics of cadenas nacionales vary. In some countries, they are enshrined in law; in others, they are informal and cooperative. In some countries, including Argentina and Venezuela, all stations are mandated to air these messages (similar in nature to Emergency Action Notifications in the United States).