Article 25. 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.
PART III - OBSERVANCE, APPLICATION AND INTERPRETATION OF TREATIES
SECTION 1. OBSERVANCE OF TREATIES
Article 26. Pacta sunt servanda
Every treaty in force is binding upon the parties to it and must be performed by them in good faith.
Article 27. Internal law and observance of treaties
A party may not invoke the provisions of its internal law as justification for its failure to perform a treaty. This rule is without prejudice to Article 46.
SECTION 2. APPLICATION OF TREATIES
Article 28. Non-retroactivity of treaties
Unless a different intention appears from the treaty or is otherwise established, its provisions do not bind a party in relation to any act or fact which took place or any situation which ceased to exist before the date of the entry into force of the treaty with respect to that party.
Article 29. Territorial scope of treaties
Unless a different intention appears from the treaty or is otherwise established, a treaty is binding upon each party in respect of its entire territory.
