French President Emmanuel Macron has said that 31 October should be the "final" deadline for Britain's much-delayed withdrawal from the European Union.
Mr Macron was among those EU leaders opposed to granting Britain a long extension of its date for divorce when it was moved from March until the end of October.
"I think this is the final, final deadline because I don't want to have the new Commission and this new executive to deal with (this)," he said, referring to the naming of new heads of major EU institutions.
"I think it is a big mistake to procrastinate."
Mr Macron was speaking at the Elysee palace in Paris with members of the International Monetary Conference.
"I do believe we now have to implement the British people's decision. Except if the British people themselves decide something else," Mr Macron said.
"That's why I was always pictured as the tough guy in the room on this Brexit issue. But I do endorse such a role."
However, Mr Macron left the door open for another extension of the Brexit deadline if Britain decided to ask for time to launch a second Brexit vote.
"It's feasible if we have the perspective of either a new referendum or a totally new scheme which would be acceptable for the 27 and our negotiator."
Mr Macron also described any possible British attempt to try and renegotiate the current deal to remove the Irish backstop as a "non-starter".