EU foreign policy chief Josep Borrell has described the ongoing tensions as a "critical situation".
Foreign ministers of the EU have met in Brussels to discuss ways to ease tensions in Bosnia in a bid to prevent the possible breakup of the Balkan country undergoing the most significant political crisis since the end of the 1992-1995 war.
Monday's meeting comes as the 26-year-old Dayton Peace Accords continue to be brought into question by the country's ethnonational leaders in what officials have described as a "critical situation".
“The nationalist and separatist rhetoric is increasing in Bosnia and Herzegovina and jeopardising the stability and even the integrity of the country,” said EU foreign policy chief Josep Borrell.
He added that “ministers will have to take a decision on how to stop these dynamics in Bosnia and Herzegovina and to avoid the country [falling] apart in pieces".
Drafted to bring the war to an end in 1995, the US-sponsored peace deal created two main administrative units in Bosnia — the Serb-dominated entity of Republika Srpska, or RS, and the Bosniak-Croat majority Federation of BiH.
The two entities share state-wide institutions — such as the tax collection system, judiciary and even the armed forces — and all actions at a national level require consensus from all three ethnic groups.
The peace agreement also created one of the most complicated political systems in the world, with a dizzying maze of jurisdictions enabling the country’s three main ethnic groups to dominate domestic politics and exert control over key decision-making processes.
Last month, the US unveiled new sanctions against Bosnian Serb leader Milorad Dodik, who has for years been advocating that the Republika Srpska should separate and unite with neighbouring Serbia.
The US has accused Dodik of “corrupt activities” that threaten to destabilise the region and undermine the US-brokered Dayton Peace Agreement.
Most EU countries also want to hit Dodik with sanctions, but Hungary, Croatia and Slovenia are notably opposed and likely to scupper any attempt to impose restrictive measures. Russia has also notably pledged support for Dodik and his associates.
Austrian Foreign Minister Alexander Schallenberg said that "the announcements of Dodik and Republika Srpska are extremely dangerous and playing with the integrity of the state, and this is for us a no-go".
He warned that Bosnia and the Balkans must not become "a playground for actors outside Europe".
Dodik, meanwhile, says he and Bosnian Serbs are being unfairly targeted and wrongly accused of corruption.
The EU is also demanding that electoral reform be passed ahead of polls in Bosnia later this year — a demand backed by Bosnian Croat leaders claiming that the current electoral law favours Bosniaks and threatening to establish their own, third entity in case their demands are not met.
"The situation in Bosnia is more worrying than ever," Josep Borrell said at an annual security conference in Munich on Sunday.
"It was never easy, but now the centrifugal tendencies are really very worrying," he added.
"I appeal to the responsibility of the political leaders of Bosnia and Herzegovina to avoid the breakup of the country," Borrell said.