The operation to clear the Calais 'Jungle' camp is to end on Wednesday night with French authorities declaring it a success.
Buses taking refugees and migrants to their new homes will stop and demolition of the camp is to be scaled up on Thursday.
The announcement came as a number of fires swept through the settlement on the third day of the operation to clear it.
A huge plume of dark grey smoke could be seen from a distance billowing over the sprawling camp as makeshift shelters that were recently homes burned.
Multiple large blazes had torn through caravans, tents and shelters in the centre of the camp a little before midday on Wednesday.
The sound of exploding gas canisters were heard as the flames ripped through what had recently been migrants' and refugees' homes.
Four migrants have been arrested in connection with the fires, said Patrick Visser-Bourdon, the Calais police commissioner in charge of the operation, amid reports British activists were responsible.
Pascal Brice, head of the Office for Refugees and Stateless People, said: "The operation will be over tonight because all the people who were leaving the Jungle are now welcomed in France, in good conditions in accommodation centres.
"It is a matter of satisfaction for the French administration because all those people now are in centres all around France and the Jungle is over."
More than 5,000 migrants and refugees have been bussed to registration centres, he said, with about 100 people waiting to be transported.
A spokeswoman for the local prefecture said around 1,500 minors had passed through the registration warehouse.
She added that the rate of demolition would be scaled up on Thursday, with larger machinery moving in.
Save the Children said it was "extremely concerned" about children both in camp and those who had not been registered as the camp went up in flames.
The Help Refugees charity reported that unaccompanied children were being sent back to the camp as registration of minors had stopped for the day.