In addition to treaties, there are other less formal international agreements. These include efforts such as the Proliferation Security Initiative (PSI) and the G7 Global Partnership Against the Proliferation of Weapons of Mass Destruction. Although the PSI has a "declaration of prohibition principles" and the G7 Global Partnership includes several statements by G7 heads of state and government, it also does not have a legally binding document that sets specific obligations and is signed or ratified by member states. Initially, international law did not accept any contractual reservations and rejected them, unless all parties accepted the same reservations. However, in order to encourage as many states as possible to join the treaties, a more straightforward reserve rule has been established. While some treaties still explicitly prohibit any reservations, they are now generally accepted to the extent that they are not incompatible with the objectives and objectives of the treaty. If a contract does not contain provisions for other agreements or measures, only the text of the treaty is legally binding. In general, an amendment to the Treaty only commits the States that have ratified it and the agreements reached at review conferences, summits or meetings of the States Parties are not legally binding. The Charter of the United Nations is an example of a treaty that contains provisions for other binding agreements. By signing and ratifying the Charter, countries have agreed to be legally bound by resolutions adopted by UN bodies such as the General Assembly and the Security Council. Therefore, UN resolutions are legally binding on UN member states and no signature or ratification is required. Currently, the likelihood of international agreements being implemented by an executive agreement is ten times higher. Despite the relative simplification of executive agreements, the President still often chooses to continue the formal process of concluding an executive agreement in order to gain congressional support on issues that require Congress to pass appropriate enforcement laws or means, as well as agreements that impose complex long-term legal obligations on the United States.
For example, the agreement of the United States, Iran and other countries is not a treaty. The distinctions are mainly related to their method of authorisation. Contracts must be advised and approved by two-thirds of the senators present, but executive agreements alone can be executed by the President.