Serbia could be blocked from joining the European Union if its president travels to Russia next month for Vladimir Putin’s Victory Day parade.

Axar.az reports, citing the Telegraph, Russian state media reported that Aleksandar Vucic would be one of the foreign dignitaries in attendance, as well as contributing military hardware to the spectacle on May 9.

In response, European officials warned Mr Vucic that his visit would be a breach of the bloc’s membership criteria and would derail his country’s EU ambitions.

“We need to ensure that they understand that certain decisions come at a cost,” said Jonatan Vseviov, the secretary-general of Estonia’s ministry of foreign affairs. “The consequence is them not joining the European Union.”

He added: “Russians have been working hard to get people to attend . . . For us this will be an important litmus test. Basically what we look at is whether or not they are on our side or playing on the other team.”

Kaja Kallas, the bloc’s top foreign diplomat, said EU foreign ministers had discussed prospective member states attending the ceremony in Moscow, at a gathering on Monday.

“What was also discussed very clearly, and said by different member states, is that any participation in the May 9 parades or celebrations in Moscow will not be taken lightly on the European side, considering that Russia is really waging a full-scale war in Europe,” she told reporters after the meeting.