European Commission President Jean-Claude Juncker has told a conference in Italy on the EU that “English is losing importance in Europe”.
Amid tensions with the UK over looming Brexit negotiations, he said he was delivering his speech in French.
“Slowly but surely English is losing importance in Europe and also because France has an election,” he said, explaining his choice of language.
He called the UK decision to leave the EU “a tragedy”.
Laughter and applause greeted his comment about the English language, and he could be seen smiling wryly.
“We will negotiate fairly with our British friends, but let’s not forget that it is not the EU that is abandoning the UK – it is the UK that’s abandoning the EU, and that makes a difference,” he said.
UK Prime Minister Theresa May has accused some EU officials of trying to influence the UK’s 8 June parliamentary election.
The Commission’s chief Brexit negotiator, French ex-commissioner Michel Barnier, is to give a speech on Brexit in a few hours’ time.
EU leaders say the UK cannot simply “cherry-pick” membership terms that it wishes to keep. A Brexit deal cannot be better than full EU membership, they stress.
The EU conference is called State of the Union, at Florence’s European University Institute (EUI).
France holds the decisive second round of its presidential election on Sunday. Top EU officials say they want liberal independent Emmanuel Macron to beat his nationalist rival, Marine Le Pen.