When an agreement is formed between two nations the mort popular term is Treaty.
That is a treaty.
A formal agreement between two or more nations is called a treaty.
a treaty is an agreement between two or more nations.
interstate compact a treaty is an agreement between two nations.
treaty
A formal agreement between foreign nations is commonly called an accord. However, they also can be called international agreements as well.
A halt to fighting by agreement between warring nations is called a "ceasefire." This temporary suspension of hostilities allows for negotiations or humanitarian efforts to take place. Ceasefires can be formal or informal and may lead to peace talks or a more permanent resolution to the conflict.
entente
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.
An alliance.
Trade embargoes
alliances?