British Premier David Cameron and French President Francois Hollande on Thursday discussed reuniting underage migrants at Calais with their families in Britain.
"We need a fast and efficient solution for unaccompanied minors," Hollande said at a summit in the northern French city of Amiens.
The leaders said that ministries should fast-track such cases. There are more than 300 minors in the port city of Calais, according to aid agencies.
French authorities have taken steps to clear part of Calais' sprawling migrant camp, whose population surged to approximately 6,000 last year. They are trying to encourage migrants to seek asylum in France.
But many are reluctant to leave a site close to what they see as the easiest route to reach Britain.
Cameron said London would commit 17 million pounds (24 million dollars) in addition to commitments made to help at Calais in the past, according to the Press Association.
Hollande warned that the situation could change if Britain votes to leave the European Union in a "Brexit" referendum on June 23.
"It's not to create fear, but to say the truth," Hollande was quoted by AFP news agency as saying. "There will be consequences if Britain leaves the EU ... including for the method of managing the migrant situation."