Serbia's EU membership hinges on its strategic choices, Kallas said after meeting Vucic and government officials in Belgrade, stressing the need for concrete reforms.

Axar.az reports, citing Euronews, Serbia's EU membership "remains a strategic goal" yet depends on a "geostrategic choice" of direction, Kallas said Thursday after meeting Serbian President Aleksandar Vucic and government officials in Belgrade, the first stop on her broader Western Balkans tour.

“From my discussions with Serbian political leadership it is clear that EU membership remains a strategic goal,” Kallas said. “However, I want to emphasise that we need to see actions also to prove and support those words.”

"Reforms are how Serbia will advance along its EU path," she added. "There are no shortcuts for membership. Real progress must be made here in Belgrade.”

The EU foreign policy chief also touched upon Vucic's trip to Russia for the Victory Day parade in Moscow, a decision widely criticised by Brussels and Kallas, who earlier warned the Serbian leader not to travel to the Russian capital for the 9 May celebrations.

"I really don’t understand why it is necessary to stand side by side with (Russian President Vladimir Putin) who is conducting this horrible war in Ukraine," Kallas added. "And President Vucic was explaining his side of the story. So, yes, we had a very extensive discussion about this."

Vucic has previously said that "Serbia and the Serbian people made a huge contribution to the victory over fascism" in World War II, and that he was in the Russian capital to celebrate that fact.