The European Union's enlargement commissioner, Marta Kos, has cancelled a planned visit to Serbia after the country's government received the body of convicted war criminal Ratko Mladic with military honours, triggering a sharp diplomatic dispute over how Belgrade commemorates one of the Bosnian War's most notorious figures.

Mladic, the former commander of the Army of Republika Srpska — the Bosnian Serb wartime military force — died on 27 August at the age of 84 while serving a life sentence at the UN detention facility in The Hague. He had been convicted in 2017 of genocide, crimes against humanity and war crimes, including his central role in the 1995 Srebrenica massacre, in which more than 8,000 Bosniak Muslim men and boys were killed. Known widely as the "Butcher of Bosnia", he was one of the most prominent figures prosecuted by the International Criminal Tribunal for the former Yugoslavia. His body was flown to Belgrade on a Serbian government aircraft on Thursday, where it was met by officials and an army guard of honour. Supporters lined overpasses along the motorcade route, displaying banners reading "Thank you, General" and "Welcome home, General."

Posting on X, Kos wrote that "the return of his remains to Belgrade reminds Europe of the darkest pages in our recent history" and condemned "the glorification surrounding his death" as "incompatible with the values on which the EU path is built." She added: "The values that underpin our common future are not negotiable." Her position was echoed by several EU member states: Belgium's foreign minister called the honours "shameful and disrespectful to the victims," while Ireland's minister for European affairs said it was "not acceptable" for senior government figures to be memorialising Mladic. Croatian Prime Minister Andrej Plenković warned that a state funeral would "close the door to the European Union." Serbian President Aleksandar Vucic dismissed Kos's statement as "extremely brief, but stupid, as usual," arguing that authorities could not simply ban citizens from showing up or prevent a funeral. A public commemoration is planned for Saturday at the Home of the Army of Serbia in central Belgrade, with the funeral scheduled for Monday at Topcider Cemetery.

The episode has significant implications for Serbia's EU accession process, which formally began in 2014 but has stalled in recent years. Candidate countries are expected to demonstrate respect for judicial rulings and the rights of victims. Civil society groups inside Serbia, including the European Movement in Serbia, have called on the government to abandon plans for state honours, warning of severe moral, legal and political damage to the country's international standing. Voices from Croatia and Bosnia — regions directly affected by Mladic's crimes — expressed dismay, while human rights organisations accused Belgrade of obstructing historical reckoning with the wars of the 1990s, which left more than 100,000 people dead across the former Yugoslavia.