Former rebel Croatian Serb leader Milan Babic has entered no plea to counts of war crimes and crimes against humanity at his first appearance before the Hague tribunal.
Babic was charged this month with war crimes and crimes against humanity for murdering and persecuting non-Serbs in an "ethnic cleansing" campaign in the early 1990s.
His lawyer told the UN International Criminal Tribunal for former Yugoslavia his client would not plead at this stage.
Judges said Babic had 30 days to do so.
Babic (47), was a central figure in the breakaway Krajina Serb republic as the collapse of the former Yugoslavia spurred Serb nationalists to fight for territory in Croatia and Bosnia.
The burly dentist is regarded by tribunal prosecutors as one of former Serbian and Yugoslav president Slobodan Milosevic's key allies during a campaign to expel non-Serbs from about a third of Croatian territory in 1991-92.
He is the latest Serb nationalist politician charged by prosecutors with taking part in a "joint criminal enterprise" to carve out a "Greater Serbia".
Milosevic and Serb hardliner Vojislav Seselj are also named as members of the group. Both men are now in The Hague, Milosevic on trial and Seselj in pre-trial detention.