'Dr Radovan Karadzic ... has requested the United Nations Security Council to enact a resolution which honours the agreement made on its behalf by Richard Holbrooke,' states a notice filed with the International Criminal Tribunal for the former Yugoslavia (ICTY) and made available to the media.
The court has dismissed an appeal by Mr Karadzic over his claim that US diplomat Holbrooke promised him immunity from prosecution in 1996 in exchange for withdrawing from public life.
Judges ruled that only a resolution of the Security Council, which created the ICTY, could limit its jurisdiction.
Mr Karadzic's letter, addressed to the current UN Security Council president Le Luong Minh, repeats his claim that Holbrooke, the architect of the Dayton peace accords that ended the Bosnian war, had promised him immunity on the council's behalf.
Mr Holbrooke, now US President Barack Obama's special envoy to Pakistan and Afghanistan, has repeatedly denied the existence of an agreement with Mr Karadzic.
The precedent set in his case would limit the ability of diplomats to make agreements to end conflicts around the world, argued 64-year-old Mr Karadzic who was arrested in Belgrade in July last year after 13 years on the run.
Mr Karadzic faces 11 charges, including for his role in the 44-month siege of Sarajevo that left 10,000 people dead and the July 1995 massacre of around 8,000 Muslim men and boys in Srebrenica.
The ICTY has repeatedly rejected the alleged agreement, saying even if it did exist it had no bearing on the court's jurisdiction.
