Standing alongside Zoran Zaev, the Former Yugoslav Republic of Macedonia’s, the European Commission President looked horrified after realising his own gaffe.
Mr Juncker called the Former Yugoslav Republic of Macedonia, Macedonia while discussing the integration of Western Balkan countries into the EU.
The eurocrat said: “I’m meeting presidents and prime ministers from the Western Balkan countries.
“Even in as the Prime Minister of Luxembourg I was in Macedonia… I mean FYROM.”
At this point, Mr Juncker realised his mistake and looks apologetically at Mr Zaev before grabbing the microphone to avoid a further blunder.
The Commission President continued: “There is nothing new, I made it perfectly clear, and thanks to the encouragement of Commissioner Johannes Hahn, that the door is open for Western Balkin countries.
“As the country of the Prime Minister is making huge progress, I am very confident a certain period of time we will take the next step.”
Mr Juncker’s gaffe is significant because the Former Yugoslav Republic of Macedonia and Greece have been embroiled in a 27-year battle of the name.
The long-running row has been the biggest stumbling block for Macedonia’s integration with the West, including Athens vetoing the country’s attempt to join Nato in 2008.
Athens argues the use of the name implies a territorial claim over Greece’s own northerly region of Macedonia.
It has been agreed only that the country can be referred to in international venues as the Former Yugoslav Republic of Macedonia or FYROM.
Mr Zaev has dispatched foreign ministers and diplomats to Athens in fresh attempts to end the tussle over the name.
FYROM’s foreign minister, Nikola Dimitrov said: “We hope that Greece will recognise the new reality in Macedonia and our honest wish for friendship.
“We expect and we hope for help and supporter European integration.”