Every independent nation has some government agency that handles foreign affairs.
In the United States it is called the Department of State, and its chief officer is the secretary of state. In Great Britain it is the Foreign Office, whose chief officer is the foreign secretary. These agencies act under the direction of the head of government to carry out foreign policies. Every foreign service agency sends out field agents who are stationed in foreign countries to protect and promote the interests of the nations from which they come. These agents are known as ambassadors .