The European Union's senior official for new memberships on Friday expressed concern about rising nationalist rhetoric and divisions in the Balkans as countries seek to join the bloc.
EU enlargement commissioner Johannes Hahn urged regional leaders to focus on promised reforms.
Hahn was speaking in Sarajevo, where he handed the Bosnian government an EU questionnaire on its readiness to join the bloc.
The EU's 28-member states accepted Bosnia's membership application in September, launching what is certain to be a long process.
Bosnia's multiple governments must answer 3,242 questions in the next six months relating to the compatibility of their economic, legal and social systems with EU standards.
"It's a kind of stress test," Hahn said.
Hahn said, however, there was a general concern about nationalist rhetoric in some countries of the region.
In Bosnia itself, divisions among its Christian Orthodox Serbs, Catholic Croats and Muslim Bosniaks have deepened.
"I can only urge everybody to abstain from this kind of rhetoric and focus on what people need — and people need jobs, they need income, they need social guarantees," Hahn said.
Bosnia hopes to get EU candidate status by the end of 2017 joining other Western Balkan countries that are at a more advanced stage of integration, including Albania, Macedonia, Montenegro and Serbia.
Croatia and Slovenia, which like Bosnia are former Yugoslav republics, are already EU members.
Prime Minister Denis Zvizdic said he hoped that political disagreements in Bosnia's Serb-dominated region and in the autonomous Bosniak and Croat federation would not block or slow down progress towards EU accession.
All groups say that EU membership is a shared goal.