Problem setting. Nowadays the problem of the provisional application of treaties can be described as actual. It is no accident that it has been the subject of the attention of the United Nations International Law Commission with the task of elaborating the most important problems of international law. Furthermore, the above-mentioned subsidiary body of the United Nations General Assembly recognized the need to analyze the provisional application of treaties, the need for the progressive development and codification of international law in respect of the topic dealt with in this article.
Аnalysis of research and publications. Aspects of the problem of provisional application of treaties are reflected primarily in the works of in the works of I.I. Lukashuk, O.V. Kyivets, O.V. Pushniak, I.I. Maryniv, T. Leber.
Target of research is to describe the legal institution of the provisional introduction of international treaties and to find reasons for its use.
Article’s main body. The article is devoted to the question of the temporary use of an international treaty as a fundamental institution of international law. The study discusses the need for provisional application of treaties. Attention was paid to the works of legal academics, who had considered this issue, their works and summaries were reviewed regarding the question under consideration. The author analyzed the formulations of the article 25 of the 1969 Vienna Convention on the Law of Treaties. Legal aspects and shortcomings were considered. First of all, it was noted that there is no definition of the temporary application of international treaties in the 1969 Vienna Convention on the Law of Treaties and article 25 of the Convention had been criticized for being difficult to understand and lacking legal precision. In the article, the author noted that in general, the provisional use takes place before the entry into force of the treaty, when countries have not yet completed the necessary internal state procedures for its entry into force and have not internationally expressed consent to be bound. The author also stressed that the application of the treaty before it enters into force or will enter in the moment when it is implemented, the parties will address to their commitments and thus the object of the treaty would disappear. The author highlighted another legal aspect of the international legal institution under consideration is that, in order to implement the institution of provisional application of treaties, A special law and regulations may be enacted in domestic law (constitutional and legislative). What is more, the author mentioned that it is appropriate to devote attention to the work of the father of the national science on the law of international treaties I.I. Lukashuk.
Conclusions. The author concluded that the institution of the provisional use of treaties is one of the key institutions in the law of treaties enabling the parties to urgently address cooperation issues. Another conclusion of the author of this article is that countries resort to this legal instrument under consideration for several reasons: urgent resolution of issues to which the relevant treaties apply; the desire of countries to adopt and immediately implement confidence-building measures; preventing time gaps in the operation of a number of international treaties, which have been successively adopted and replace each other on the same subject.