European Union foreign policy chief Kaja Kallas issued a firm warning on Tuesday, declaring that any move to undermine Bosnia’s territorial unity, sovereignty, or constitutional framework is unacceptable. Her remarks come amid growing concerns over separatist actions by Bosnian Serb leaders.

Bosnia is currently facing its most severe political crisis in decades, triggered by the February conviction of Bosnian Serb leader Milorad Dodik. He received a one-year prison sentence and a six-year political ban for ignoring rulings from the international high representative overseeing the country’s peace framework. In defiance, Dodik — who leads the semi-autonomous Republika Srpska — pushed through laws effectively severing the region from state-level judicial and law enforcement bodies.

This has spiraled into a serious legal and political standoff, positioning Dodik and his backers, including Russia and Serbia, in direct opposition to the U.S. and the EU. The conflict is widely viewed as one of the most serious threats to Balkan stability since the wars of the 1990s.

Speaking during her visit to the EU’s peacekeeping mission, EUFOR, in Sarajevo, Kallas accused Republika Srpska's leadership of destabilizing Bosnia’s legal and constitutional structure. “These actions threaten the core freedoms of all its citizens,” she said.

Kallas also pointed to the EU’s recent decision in March to reinforce EUFOR with several hundred additional troops as a tangible demonstration of its enduring commitment to safeguarding peace and stability in Bosnia and Herzegovina.

While urging local political actors to engage in dialogue and find cooperative solutions, Kallas cautioned against nationalist rhetoric and divisive moves. “These are not only harmful,” she said, “but also run counter to the European aspirations Bosnia and Herzegovina has committed to.”

Bosnia remains divided into two entities—the Serb-led Republika Srpska and the Bosniak-Croat Federation—linked by a fragile central government. The post-war political structure, overseen by international authorities, was designed to prevent a return to conflict following the 1990s war, which claimed 100,000 lives.