The Serbian government has raised to 10m euros (£8.7m, $13.8m) its reward for information leading to the capture of war crimes suspect Ratko Mladic.
It said that by raising the reward tenfold it showed a clear commitment to removing the final obstacle to Serbia's entry into the European Union.
Gen Mladic is accused by international prosecutors of genocide while leading Bosnian Serb forces in 1992-95.
Aged 68, he has been on the run since the end of Bosnia's civil war.
The reward for the capture of Croatian Serb leader Goran Hadzic was also raised, from 250,000 to 1m euros, said Serbian deputy war crimes prosecutor Bruno Vekaric.
"These two men have kept the whole nation hostage - also their families and future generations," Mr Vekaric said.
Serbia was demonstrating "clear political will to remove the last remaining obstacle on its path towards the EU," he added.
EU foreign ministers have said Serbia's assistance in arresting and bringing to trial the two suspects "would be the most convincing proof" of its future co-operation with the international war crimes tribunal in The Hague.
Full co-operation with The Hague is a condition for Serbian accession.
UN court officials believe he may be hiding in Serbia, where he is still seen by some as a hero.
Gen Mladic was jointly indicted along with former Bosnian Serb leader Radovan Karadzic in 1995 for war crimes.
Mr KaradzicW is now being tried at The Hague after his capture in 2008 in Belgrade, where he was living in disguise and under a false name.