This study discusses the status of civilian foreign citizens who participated in the war to defend Ukraine under international humanitarian law and state responsibility for foreign civilians participating in the war to defend Ukraine under international humanitarian law. The purpose of this research is: to analyse the status of foreign nationals, especially those contained in the Geneva Convention of 1949; and accountability countries that are fair to foreign nationals based on humanitarian law international. The method used in this research is normative. Results from this research that the status of foreign citizens who are involved in fighting for Ukraine are entitled under International Humanitarian Law treated as prisoners of war and entitled to equal treatment of humans. Actions committed by foreign civilian citizens, from each country are obliged to provide accountability to the aggrieved party. The rights of foreign nationals are protected by conflicting countries but do not reduce the privileges of the state against its own citizen. The link between international human rights law and law international humanitarian law is also one of the basic reasons for detaining power does not have the right to commit acts of cruelty.