Radovan Karadzic’s lawyer has said the former Bosnian Serb leader will conduct his own defence if transferred to the Hague.
He was arrested in a Belgrade suburb on Monday after 11 years on the run.
He is wanted over atrocities committed during the Bosnian war.
A judge in Belgrade has begun extradition proceedings against Karadzic.
But his legal team have said they will fight the decision and will try to drag out the process.
His lawyer, Svetozar Vujacic, said: “I don’t think they’ll accept my appeal but I want to disrupt their plans to extradite him. I’ll use the legal opportunity to appeal on the last possible day, Friday. Radovan is feeling great, he’s much calmer than I am and in good health.”
There is tight security around the prison where he is being held, after rowdy protests in Belgrade by supporters of the ex-Bosnian Serb President.