“Dear British friends, you are leaving the European Union but you are not leaving Europe,” the president wrote in an open letter published Saturday by The Times of London.

This year marks the 80th anniversary of Charles de Gaulle's dramatic June 18, 1940, appeal from London, where he had escaped with the remnants of France's army, for French citizens to resist while awaiting UK and US help in fighting Nazi Germany.

“The French know what they owe the British, who allowed our Republic to live. I am coming to London in June to award the city the Legion d'Honneur, in tribute to the immense courage of a whole country and people,” Macron wrote.

He also noted that “the UK has been a central player in the European project… a more influential player than the British have often themselves imagined.”

But Macron acknowledged that the uncertainties surrounding Brexit are far from settled, not least the fallout on trade relations.

“Ease of access to the European market will depend on the degree to which the European Union's rules are accepted, because we cannot allow any harmful competition to develop between us,” he said.

The French president was largely alone in acknowledging Britain's official departure from the EU as of midnight (2300 GMT) Friday, ending 47 years of participating in the Continent's project for an “ever-closer union among the
people's of Europe.”

In a television address Friday, he called Brexit a “historic warning sign” indicating that “we need more Europe.”