Because the sustainable finance market is growing rapidly all over the world, there is a need for harmonized standards to regulate it at the national and international levels. Work toward introducing a green bond mechanism in Russia is currently being carried out by VEB.RF together with the Ministry of Economic Development of Russia and the Bank of Russia. The article outlines problems arising from the lack of uniform and comprehensive international criteria for evaluating the effectiveness of green financing. Without such standards, data on the positive effects of green investment are not comparable across countries. Unless Russian green finance standards can be harmonized with international ones, it will be impossible for Russian projects to attract investment by placing financial instruments (such as bonds) on foreign exchanges. It should also be noted that the restrictions imposed by economic sanctions require Russian regulators to ensure that sustainable financing mechanisms comply with the international approaches in order to attract sustainable investment even from the countries that have not acceded to these restrictions. This is because those countries nevertheless take part in the international harmonization of national approaches to sustainable financing, including those that apply to EU countries. For example, some of the countries that have not agreed to sanctions (Argentina, China, India, Indonesia, Malaysia, etc.) are harmonizing their sustainable finance standards through the International Platform for Sustainable Finance (IPSF). This study includes a comparative analysis of the existing standards for green finance in key jurisdictions (EU, China, Russia), identifies potential barriers arising from Russia’s green finance standards that would discourage foreign green investment in instruments from Russian issuers, and finally highlights the risks incurred by failure to harmonize Russian standards with the international ones.