Question

What is a formal agreement between two or more countries about trade, peace, and other matters called?

Answer 1

A formal agreement between countries about trade, peace and other matters is called a Treaty.

It is the commitment of the parties to assume obligations among themselves, and if any of them fail to do so they can be found liable under international law.

Some examples of Treaties are: Treaty of Warsaw (1920), North American Free Trade Agreement (NAFTA, 1994) , Paris Agreement (2015).

Answer 2

I believe its called a  treaty