A multilateral treaty or multilateral agreement is a treaty to which two or more sovereign states are parties.
Examples of multilateral treaties include the Convention Relating to the Status of Refugees, the United Nations Convention on the Law of the Sea, the Geneva Conventions, and the Rome Statute of the International Criminal Court.
Pope Francis argues in his encyclical letter Fratelli tutti (2020) that "preference should be given to multilateral agreements between states, because, more than bilateral agreements, they guarantee the promotion of a truly universal common good and the protection of weaker states.
Due to the limited nature of a plurilateral treaty, the full cooperation of the parties to the treaty is required in order for the object of the treaty to be met.
This principle is codified in international law by article 20(2) of the Vienna Convention on the Law of Treaties: When it appears from the limited number of the negotiating states and the object and purpose of a treaty that the application of the treaty in its entirety between all the parties is an essential condition of the consent of each one to be bound by the treaty, a reservation requires acceptance by all the parties.