"Enlargement is the priority for the European Union, and if our candidates deliver, then we have to deliver, too," Enlargement Commissioner Marta Kos said ahead of a meeting of EU foreign ministers in Brussels earlier this month.

As proof that the EU is moving beyond rhetoric, Kos pointed to the fact that for the first time in 17 years, the bloc in April established a working group to draft the accession treaty for a candidate country: Montenegro.

"There is no clearer signal that the EU sees Montenegro as its next member state," Strahinja Subotic, program manager and senior researcher at the European Policy Centre (CEP) in Belgrade, told DW.

Enlargement: a geopolitical and security issue

Russia's invasion of Ukraine in 2022 put the subject of enlargement back at the center of European politics, turning what had long been a technical process into a geopolitical and security issue.'Enlargement is the priority for the European Union,' says EU Enlargement Commissioner KosImage: Dursun Aydemir/Anadolu/picture alliance