A travel advisory is a public notice issued by a government agency

Government agency

A government or state agency is a permanent or semi-permanent organization in the machinery of government that is responsible for the oversight and administration of specific functions, such as an intelligence agency. There is a notable variety of agency types...

 to provide information about the relative safety of travelling to or visiting one or more specific foreign

Foreign

Foreign may refer to:*Foreign corporation, a corporation that can do business outside its jurisdiction*Foreign key, a constraint in a relational database*Foreign language, a language not spoken by the people of a certain place...

 destinations. The purpose is to enable travelers make an informed decision about a particular travel destination, and to help travellers prepare adequately for what may be encountered on their trip.

Travel advisories may relate to issues such as inclement weather, security matters, civil unrest or disease.

Travel advisories from the United States Department of State

United States Department of State

The United States Department of State , is the United States federal executive department responsible for international relations of the United States, equivalent to the foreign ministries of other countries...

 are called warden messages.