Ambassador-at-large

An ambassador-at-large is a diplomat of the highest rank or a minister who is accredited to represent his country internationally.

Unlike an ambassador-in-residence who is usually limited to a country or embassy, the ambassador-at-large is entrusted to operate in several usually neighboring countries, a region or sometimes hold a seat in an international organization like the United Nations and the European Union. In some cases an ambassador-at-large may even be specifically assigned a role to advise and assist the state or a government in particular issues. Historically, presidents or prime ministers have designated special diplomatic envoys for specific assignments, primarily overseas but sometimes also within the country as an ambassador-at-large.

According to international protocol, ambassadors and ambassadors-at-large are officially styled and addressed as His/Her Excellency, or Mister/Madam Ambassador. The title may be abbreviated in official correspondence as H.E.

The US President appointed the first official specifically to bear the title of ambassador-at-large on 12 March 1949, under the authority vested in Article II, Section 2 of the U.S Constitution to deal with specific foreign policy issues which have been frequently, but not always, spelled out in their commissions.

Ambassador-at-Large positions in the diplomatic corps of the US State Department include:

...
Wikipedia