Which term describes a formal agreement extending amnesty to another country?

The term that best describes a formal agreement extending amnesty to another country is an executive agreement. Executive agreements are agreements made between the United States and other nations that do not require the approval of the Senate. These agreements can cover various matters, including the extension of amnesty, and reflect the president's authority to conduct foreign relations.

Understanding the context of executive agreements is crucial, as they are often used for military or trade processes and allow for rapid diplomatic engagement without the lengthy Senate ratification process. In contrast, a pardon refers to forgiveness for a crime, typically granted by a president to an individual, rather than a formal agreement between nations. A reprieve involves delaying a punishment, usually in a legal context, and does not pertain to international agreements. The War Powers Resolution is legislation that outlines the procedures for the president in deploying military forces, but it does not relate to amnesty or agreements with other countries.