Five days into a French operation to clear the Calais Jungle, France has lashed out at apparent British criticism of the way children are being treated while thousands of migrants are resettled across France and the camp is destroyed.

France's home office minister Bernard Cazeneuve expressed "surprise" in a statement late on Thursday about comments by his British counterpart and sought to remind Britain of its responsibilities with regard to the stranded young people.

ITN said in a website report British Home Secretary Amber Rudd had spoken to Cazeneuve "to stress the need for children who remain in Calais to be properly protected".

The French government said Cazeneuve and his housing minister, Emmanuel Cosse, "learned with surprise the declarations of Ms Amber Rudd, Britain's interior minister".

"The French ministers hope...the United Kingdom will quickly execute its responsibilities to take in these minors, who hope to come to the United Kingdom. This is the best way to give them the protection they are due."

The French statement followed widespread media reports of unsupervised children sleeping rough around the port town since the clearance operation was launched, even though some 1,451 minors have been housed separately near the camp.

France says Britain has accepted 274 children from among this group.

Thousands of migrants had until this week been camped near Calais in the hope of making the short journey across the sea to Britain by leaping on trucks and trains or walking through the Channel tunnel.

European Union rules say Britain must take in unaccompanied children who have family ties in the country under so-called Dublin rules. An amendment to those rules adopted in Britain this year states that such minors whose best interests are served by doing so should also be admitted.