Emmanuel Macron has said he is “not sure” a post-Brexit trade deal will be reached by the end of the transition period on 31 December.
The French president predicted the talks would be “very tough” as he tried to reassure his country’s farming and fishing industries.
“It’s going to be tense,” he added during a visit to a farm show in Paris. “I am not sure that we will have a global deal by the end of the year.”
It comes after the French foreign minister warned that Britain and the EU would “rip each other apart” during the negotiations, which are due to begin on 2 March.
Boris Johnson has said he wants a Canada-style deal, which removes most tariffs on goods traded between the two countries.
UK ministers will meet on Tuesday to sign off on the formal trade mandate document which will frame Britain’s negotiating aims before it is published on Thursday.
“The UK has made clear a number of times, and will reiterate, its desire for a Canada-style deal,” Downing Street said in a statement.
However, EU chief negotiator Michel Barnier has said Britain cannot have that deal unless it agrees to aide by the bloc’s regulations.
Mr Macron promised farmers on Saturday that he would safeguard agricultural subsidies under the EU’s Common Agricultural Policy.
He also voiced support for the fishing sector, which risks losing current access to British waters.
“Boris Johnson has a card in his hand and it is fishing and with that he will try to gain access to the market,” he said.
The French president said he would seek compensation for French fishermen for any losses suffered.
Additional reporting by agencies
