Abstract
The relevance of the question of the use of the veto right is quite high both in constitutional and in international public law. The right of veto is an instrument for maintaining a balance of “checks and balances’’ both between branches of power within a single state and between participants in international organizations. The purpose of the research in the work is to examine the essence, historical and legal aspects of development, the current state, problems and prospects for the use of the veto right in both constitutional law and international public law. The main results that were achieved during the research were: determining the essence of the veto right, the historical aspects of the emergence and development of this right; the specific features of the use of the veto in international organizations. Prospects for further research: the development of the study in terms of the possibilities for reforming the UN Security Council, taking into account the current realities, the use of the veto by the permanent members of the UN Security Council, the change in the number of permanent members of the UN Security Council.