It is called an alliance or it could be a treaty depending on the context of said agreement
A formal agreement between two or more nations is called a treaty.
a treaty is an agreement between two or more nations.
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.
interstate compact a treaty is an agreement between two nations.
Treaty
Internationalism.Treaty
A Treaty.
A contract is a legally binding agreement between two or more parties.
A treaty is a formal agreement between the governments of two or more countries.
A formal agreement between two countries is called a treaty or a pact.
A treaty is an agreement under international law between two or more sovereign states or international organizations. It's also known as an agreement, protocol, convention, or pact.
When two nations agree to work together, it is called a bilateral agreement or a partnership. This can involve various forms of cooperation such as trade agreements, military alliances, or joint development projects.