“Treaty” means an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation. Vienna Convention on the Law of Treaties, May 23, 1969, art. 2(1)(a), 1155 U.N.T.S. 331.
2. Transmission to Senate
Under U.S. law, a treaty is an agreement made "by and with the advice and consent of the Senate," pursuant to Article II, Section 2, Clause 2 of the Constitution. In order to be considered a treaty under U.S. law, the document must go through a second set of steps in which it is approved by the Senate.
3. Entry into Force
After approval, the President may proclaim that the treaty has entered into force.
Remember that there are other international agreements entered into by the United States that do not constitute treaties and do not require the advice and consent of the Senate to be binding. Such agreements are generally referred to as executive agreements (see below).
International agreements brought into force on a constitutional basis other than with the advice and consent of the Senate are "international agreements other than treaties" and are often referred to as "executive agreements." Congress generally requires notification upon the entry of such an agreement.