The focus of most of the controversies relating to the law of expropriation is an the issue of compensation and whether that issue is to be determined under international law.
The proposition that compensation in the event of expropriation of the property of an alien must be determined under international law was adopted in U.N. General Assembly Resolution 1803 (XVII) on Permanent Sovereignty over Natural Resources, (adopted in 1962 by the General Assembly by 87 votes to two, with twelve abstentions an the part of ten Communist states and Ghana .and Burma), which refers to "appropriate compensation,- in accordance with the rules in force in the State taking such measures in the exercise of its sovereignty and in accordance with international law."
[The author elaborates on the definition of expropriation and the requirement of compensation.]