The EU's foreign policy chief said that Bosnia & Hergezovina had fallen behind on reforms needed to ready it to become a member state.
The European Union is committed to Bosnia and Herzegovina joining the bloc but has warned that there is still much work to be done.
Bosnian Prime Minister Zoran Tegeltija was in Brussels on Tuesday to discuss with the EU's foreign policy chief Josep Borrell the country's progress on accession to the EU.
The talks took place against the backdrop of mounting skepticism in Europe about enlargement. An unofficial diplomatic note from April allegedly advocated the redrawing of the borders of Western Balkan nations and has led to scepticism about Brussels' commitment to the region.
It proposed Serbia, Croatia, and Albania be expanded to swallow up parts of neighbouring Bosnia, North Macedonia and Kosovo.
Despite assurances that the bloc would stick to the country's accession process, Borrell reminded the Tegeltija that his country still has a lot of work to do.
"The EU reiterates its unequivocal commitment to Bosnia and Herzegovina's EU perspective as a single, united and sovereign country and our commitment to remain firmly as its side," Borrell said during a joining press conference with Tegeltija on Tuesday.
"I also encourage Bosnia Herzegovina to step up its alignment with the common [EU] foreign and security decisions," he added.
"And I regret that the rate of alignment has dropped in the first months of this year. This is certainly not in line with the aspirations to become a European Union candidate country."
Bosnia and Herzegovina has slowed down its implementation of the necessary reforms: rule of law issues, the end of the glorification of convicted war criminals and electoral reform.
For Nedzma Dzananovic, a political analyst at the University of Sarajevo, the prospect of Bosnia and Herzegovina joining the EU is as remote as ever.
"Braindead, comatose, catatonic, whichever term or phrase we use, even if we use euphemisms, it is quite clear that the process that started more than two decades ago is in deep crisis and has not delivered the results that we require," Dzananovic told Euronews.
"It is necessary to rethink the process, to revive the process in a meaningful way and give an honest account of what the European Union can offer."
Dzananovic also warned that further delay to the accession talks will be harmful for the region and only play into the hands of Russian and Chinese ambitions.