The relevance of the study is due to the lack of proper legal regulation in the field of legal determination of the procedure for executing a court decision under which a foreign state (aggressor or occupier) acts as a debtor. The purpose of the study is to develop a mechanism for effective protection of the rights of Ukrainian recoverers in cases of compensation for damage by the state aggressor through the prism of proper enforcement of court decisions in these categories of cases. In the course of the study, a number of general scientific and industry methods are applied, in particular, the method of analysis and synthesis, system, structural-functional, dialectical, historical, and hermeneutical methods. The paper analyses the legal positions of the European Court of Human Rights regarding the right to appeal to the court in cases of debt collection from a foreign state as compensation for material and/or moral damage caused to individual applicants. The study examines the practice of the national courts of Ukraine in cases of claims of individuals – citizens of Ukraine against a foreign state for compensation of material and (or) moral damage caused by the invasion of the territory of Ukraine. It is established that a state cannot be allowed to use the doctrine of sovereign immunity as a shield for its violations of other doctrines of international law, such as international law on armed conflicts. The expediency of applying the model of functional (limited) immunity, which is becoming increasingly widespread and recognised by advanced countries of the world, is justified, considering its practicality and compliance with modern requirements for the development of society and leading trends in the development of international law. The results of the study can be used for further scientific developments of the outlined problems in the rule-making process, both in the conclusion of international treaties and in national legislation and in the law enforcement process in the implementation of legal proceedings