Article 25 Vienna Convention on the Law of Treaties

Provisional application

1. A treaty or a part of a treaty is applied provisionally pending its entry into force if:
   (a) the treaty itself so provides; or
   (b) the negotiating States have in some other manner so agreed.
2. Unless the treaty otherwise provides or the negotiating States have otherwise agreed, the
   provisional application of a treaty or a part of a treaty with respect to a State shall be terminated if that
   State notifies the other States between which the treaty is being applied provisionally of its intention not to become a party to the treaty.

See also: Article 24 Vienna Convention on the Law of Treaties