European Foreign Policy chief Catherine Ashton and her envoy to the Balkans Robert Cooper have been caught on camera wondering what Serbia's new President Tomislav Nikolic looks like.

Despite the fact that Serbia is a candidate for EU membership and that Ashton’s service is deeply concerned over the nationalist past of President Nikolic, a former ally of former Slobodan Milosevic, the pair have not familiarized themselves with a photograph of him before sensitive talks, The Telegraph reported.

As she prepares to enter the room to welcome Nikolic before the critical negotiations, Ashton panics because she does not know whose hand to shake in greeting.

“Robert, somebody has got to come with me because I don’t know what he looks like,” she says, turning back from the meeting room.

Robert Cooper, who is the EU’s lead negotiator with Serbia and a senior British diplomat, replies: “Nor do I.”

Getting increasingly anxious and as the Serbian leader waits in the room, Lady Ashton asks urgently, “Who knows, who knows what he looks like?”.

A full blown diplomatic crisis is only averted when a more junior official, whose face cannot be seen, curtly injects to say, “I have a picture.”

After a short pause the film, which has become a hit on Twitter and been likened to the political satire The Thick Of It, shows Lady Ashton warmly greeting a man who she would not have recognized just a few seconds before.

The Telegraph points out that in the run-up to the talks, President Nikolic, who was elected on 21 May, alarmed the EU by insisting that the town of Vukovar in Croatia, which joins the EU next year belongs to Serbia.

He also claimed that Srebrenica – which EU institutions designate as a Serb genocide of Muslims – was not genocide.