Mladi, 79, was sentenced to life in 2017 after being found guilty of genocide for atrocities committed during the Bosnian War from 1992 to 1995.
Tuesday’s decision ends the last major Balkan war crimes trial before a United Nations court.
Mladi was charged with two counts of genocide and nine crimes against humanity and war crimes for his role in the conflict in the former Yugoslavia, where 100,000 people were killed and another 2.2 million displaced. He was found not guilty on one charge of genocide, but received a guilty verdict on each of the other 10 counts.
The trial, which opened in 2012, took place at the International Criminal Tribunal for the former Yugoslavia in The Hague, Netherlands. An ad-hoc court was established to try crimes committed during the Balkan conflict.
Mladic was accused of running an ethnic cleansing campaign, including the killing of thousands of Muslim men and boys in Srebrenica in July 1995. It is the largest massacre in Europe since World War II.