Serbia pressured to join EU sanctions on Russia

She spoke after a tour of Western Balkan capitals, which the EU is trying to pull closer in the face of Russian aggression in Europe.

All the EU hopefuls in the region have mirrored EU blacklists and economic sanctions on Moscow over the past seven months, but Vučić has maintained friendly ties with Russian president Vladimir Putin.

Vučić restated Serbia's support for Ukraine's territorial integrity. Serbia also voted against Russian annexation of Ukrainian territories at the UN on 13 October.

But Vučić made a prickly remark about Western support for Kosovo independence, in a hint of underlying tensions.

"Sometimes we ask ourselves, why hasn't Serbia's territorial integrity been respected?," he said on Friday.

Serbia and Kosovo are currently embroiled in a dispute on car number plates and on autonomy for Serb municipalities, in a nervous security environment in the region.

Von der Leyen urged them to resolve their differences via dialogue. "I'm deeply convinced this is both doable and possible," she said.

Russia sanctions aside, Vučić did pledge to align Serbia with EU visa-free policy following European complaints on immigration.

EU countries had warned Serbia's visa perks could be suspended after it was found letting people from Burundi, Cuba, India, Turkey and Tunisia come to claim asylum in Europe more easily.

Von der Leyen visited Belgrade after speaking in Sarajevo earlier the same day.

"The door of the European Union is open, please seize the opportunity and use this invitation, and it is up to you now," she said in Bosnia.

The EU Commission has recommended member states grant Sarajevo EU candidate status in December — a landmark legal step on its EU journey.

Political and ethnic divisions in Bosnia have held back progress in terms of EU reforms, amid threats by the Bosnian Serb entity to break away as well as disputes on electoral law reform.