ФІНАНСОВО-ІНСТИТУЦІЙНИЙ МЕХАНІЗМ ЗАБЕЗПЕЧЕННЯ ОБОРОННИХ ЗАКУПІВЕЛЬ В УМОВАХ ВОЄННОЇ НЕВИЗНАЧЕНОСТІ

Problem statement. The full-scale armed aggression against Ukraine has significantly transformed the conditions for the functioning of public finance and defense procurement system, exacerbating the problem of balancing between resource efficiency and the requirements of accountability, transparency, and economic efficiency. Traditional public procurement approaches have proven to show a reduced ability to adjust to the conditions of military uncertainty, which necessitates a scientific rethinking of the financial and institutional mechanism for meeting the needs of the Armed Forces of Ukraine. The purpose of the article is to summarize theoretically and substantiate the components of the financial and institutional process of organizing defense procurement under martial law, taking into account resource scarcity, security risks, and the requirements of international partners. The object of the study is the financial and institutional transformation of the defense procurement system of Ukraine under the influence of military factors. Research methods. The research has used systemic and institutional approaches, methods of structural and comparative analysis, generalization of international practices, as well as logical and analytical methods of researching financial instruments and institutional norms for regulating procurement processes. The research hypothesis is based on the assumption that the effectiveness of defense procurement during wartime is determined by the consistency of the elements of the financial and institutional mechanism, which ensure the quality of the institutional architecture, the availability of multi-level control instruments, and the ability of the state's financial system to adapt to a high level of uncertainty. Presentation of basic material. The article analyzes the key components of the financial and institutional mechanism for providing the defense sector, in particular the features of budget financing in the context of limited domestic resource base and the growing role of foreign aid. It summarizes the international experience and standards of NATO, SIPRI and Transparency International regarding the institutional organization of the defense sector. It also reveals the functional role of specialized procurement agencies as key institutional entities, as well as the importance of financial control instruments, digital platforms and mechanisms for separating the functions of planning, contracting and auditing in strengthening sustainability of the defense procurement system. Research originality and practical significance. The scientific novelty lies in the development of a comprehensive model of a financial and institutional mechanism that combines financial flows and regulatory institutions into a single procurement management strategy in wartime conditions. The practical significance of the results obtained lies in the possibility of their use for institutional improvement of state policy, increasing the effectiveness of the use of financial resources and strengthening the trust of international partners. Conclusion and prospects for further research. It has been verified that financial and institutional support of defense procurement is a dynamic structure that requires constant adaptation of legal norms and financial algorithms. Further research should be directed towards the development of quantitative indicators for assessing the effectiveness of this mechanism and introduction of innovative anti-corruption safeguards.