<P> An ambassador is an official envoy, especially a high - ranking diplomat who represents a state and is usually accredited to another sovereign state or to an international organization as the resident representative of their own government or sovereign or appointed for a special and often temporary diplomatic assignment . The word is also often used more liberally for persons who are known, without national appointment, to represent certain professions, activities and fields of endeavor such as sales . </P> <P> An ambassador is the ranking government representative stationed in a foreign capital . The host country typically allows the ambassador control of specific territory called an embassy, whose territory, staff, and vehicles are generally afforded diplomatic immunity in the host country . Under the Vienna Convention on Diplomatic Relations, an ambassador has the highest diplomatic rank . Countries may choose to maintain diplomatic relations at a lower level by appointing a chargé d'affaires in place of an ambassador . </P>

What is the job of the us ambassador