No
A formal agreement between two or more nations is called a treaty.
A treaty. This bit is by Artic-Fox: An agreement between nations is called a treaty (so said above). A good example of this is the war between allied and axis. WWI they had made a treaty, however Hitler of so, ripped it up, causing...WWII!
A formal agreement between foreign nations is commonly called an accord. However, they also can be called international agreements as well.
interstate compact a treaty is an agreement between two nations.
An alliance.
An agreement between two or more states is called a multilateral agreement. Many of the agreements are to do with trade or collaboration in international development.
Concordat - "An agreement or treaty, esp. one between the Vatican and a secular government relating to matters of mutual interest."
Concordat - "An agreement or treaty, esp. one between the Vatican and a secular government relating to matters of mutual interest."
A concordat is an agreement between the pope and a ruler of a country.
contact
Alliance
It is called an alliance or it could be a treaty depending on the context of said agreement