De Montchalin was speaking a day after British MPs approved a bill that could force Prime Minister Boris Johnson to delay Brexit until January or later.
“It's not because a problem is complicated that by diluting it over time and delaying it for three months without changing anything, it will be resolved,” she told France's Radio Classique.
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The French Europe Minister Amelie de Montchalin says the British 'need to tell Europe what they want'. Photo: AFP
“When I hear the British saying 'Give us three months more and we will solve the problem', we can see that another six months would not solve the problem, nor another three months.
“They have to be able to tell us what they want,” she said.
MPs voted three times to reject a deal negotiated by Johnson's predecessor Theresa May with the EU while at the same time making clear they opposed leaving the EU without an agreement.
“We know what they don't want but we are still struggling to understand what they do want,” De Montchalin said, describing the situation as “a bit blocked”.
Initially scheduled for March 29th, Brexit has already been delayed twice due to the failure of Britain's parliament to agree on the manner of the country's exit from the EU.
Johnson has vowed to take Britain out of the union by October 31st, regardless of whether he has an agreement with the EU.
De Montchalin said France was continuing to prepare for the possibility of a no-deal Brexit.
Foreign Minister Jean-Yves Le Drian said on Tuesday that he considered it “the most likely scenario”.
De Montchalin also called it a “very strong possibility.”