Migrants carry their belongings as they walk on a road near makeshift shelters on the eve of the evacuation and dismantlement of the camp called the "Jungle" in Calais, France, October 23, 2016. [Photo/Agencies]

CALAIS, France - Aid workers accused France and Britain on Sunday of failing more than 1,300 unaccompanied child migrants whose future remained uncertain just a day before the French government begins dismantling the camp where they are holed up.

Charities operating in the makeshift camp dubbed the "Jungle" near Calais have criticised the slow pace at which British and French officials have processed the papers of children fleeing countries such as Syria, Afghanistan and Eritrea.

The UK government has prioritised children and youths who can claim family ties in Britain and on Friday a French Interior Ministry official said they were still negotiating over hundreds more with no such connections.

"All this should have been done a long time ago," Francois Guennoc from the charity Auberge des Migrants said.

Allaodil, a Sudanese boy who says he is 14, was wandering on Sunday through the Jungle's garbage-strewn mud alleyways, shivering underneath a blanket.

"My brother has been in the United Kingdom, in Glasgow, for three years and has a job there," said Allaodil in faltering English, adding that he wanted to join his elder sibling.

He said the British authorities were aware of his case but still did not know whether he would be granted asylum in Britain or forced to relocate in France.