Ukraine is on the verge of joining the European Union, which requires, on the one hand, the transformation of the regulation of banking activity in accordance with the standards adopted by it, and on the other hand, the implementation of the concept of sustainable financing in all spheres of public life, including the banking system. Recently, a stable trend has emerged in the countries of the Euro zone, which consists in liaison of the mechanism of regulation of banks’ activity to the goals of sustainable financing, which makes it necessary to do changes to the existing standard of requirements for the capital of credit institutions (CI) and to regulate its adequacy. The mentioned metamorphosis has also spread to the banks of Ukraine, which are only taking the first steps in the direction of introducing the key principles of sustainable financing into their practical work. Along with the above, in the near future the domestic banking sector may face the problem of "greening" the mechanism of regulation of their activity according to European standards, directives, regulations and guidelines. Solving this extremely difficult problem will require the NBU to take decisive and, at the same time, well-balanced measures, which would not hinder the active development of investment and lending in a sustainable economy. The aim of the study is to reveal the key provisions of the regulation of banks in the EU, to determine the vectors of their change in accordance with the goals of sustainable financing, as well as to develop recommendations for the banking sector of Ukraine. In this research, methods of scientific knowledge were used, in particular: observation, theoretical generalization, abstracttion, comparison, analysis and synthesis, induction and deduction. The main provisions of the Directive on capital requirements and regulation of capital adequacy of banks in the European Union are outlined. The essence of harmonious finance and the stages of its transformation in EU countries are revealed. The ecological vector of the regulation of banks’ activities was considered, and the difficulties and prospects of its implementation in the banks of Ukraine were determined. A "chain" of step-by-step implementation of the NBU’s "environmental" regulatory initiatives in Ukrainian banks is proposed based on the best European practices and the possibilities of their implementation in a country at war.