The 62-year-old EU commissioner, who has held the post since 2014, made the sarcastic comment after an long lunch in the country, where the latest meeting of EU heads is underway.
The lunch, which included traditional Maltese dishes of cauliflower soup, stewed beef and olives and lampuki pie, was accompanied by a selection of local wine.
Jean-Claude Juncker enjoys a glass of wine with a meal (archive image0
Mr Juncker then attended a press conference along with Donald Tusk, the President of the European Council, and the Maltese prime minister Joseph Muscat, who is also the summit host.
The trio had been discussing their fears that both the US President Donald Trump and Vladimir Putin pose a threat to the EU as well as the wider world and the international order.
Jean-Claude Juncker (R) enjoys a glass of wine with German Chancellor Angela Merkel (archive image)
A journalist posed the question: “Who’s the biggest threat to the EU?”
While both Mr Tusk and Mr Muscat were discussing the issue, the former Prime Minister of Luxembourg interrupted them to state: “Me.”
European Commission President Jean-Claude Juncker arrives for the EU Malta summit
Jean-Claude Juncker during the press conference with Donald Tusk and Joseph Muscat
The comment was interpreted as being a joke by diplomatic aides but not as a funny one, as one aide described the comment as being “inappropriate”.
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The insider told the Times: “This is not a laughing matter. Perhaps lunch was too long.”
Jean-Claude Juncker (R) at the press conference with Donald Tusk (R)
Joseph Muscat (L), Donald Tusk (C) and Jean-Claude Juncker (R)
Juncker's many signs of affection
Wed, January 18, 2017
Jean-Claude Juncker is a Luxembourgish politician. Since 2014, Juncker has been President of the European Commission, which is the European Union Executive Branch.
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While there has been gossip circulating in Brussels over Mr Juncker’s alleged drinking habits, he has denied he has a drink problem, including enjoying a glass of cognac for breakfast.
Mr Juncker has previously been forced to deny he has a drinking problem in an interview with the left-wing French publication Liberation.
Jean-Claude Juncker speaking to German Chancellor Angela Merkel
He said: ”You think I’d still be in office if I was having cognac for breakfast? It really makes me sad and it has even led my wife to question if I lie to her, as I do not drink when I'm home."