The Romanian law expert said President Alyaksandr Lukashenka's authoritarian government will react with triumph to this and victims of repressions will lose "a necessary tool" to defend their rights.
United Nations' Human Rights Council agreed that Belarus and Cuba will be taken off a list of countries whose rights records receive special scrutiny.
At a meeting of the 47-nation council in Geneva, independent monitors who studied the human rights records of Belarus and Cuba were not reappointed.
Russia is reported to have led demands for the end of the mandate of the monitor for Belarus.
Belarus and Cuba are accused of human rights abuses, particularly of political rights.