The Children's Commissioner for England has called on authorities in France to speed up processing scores of lone child asylum seekers who may be eligible to come to the UK.
Anne Longfield has written to the French government asking for urgent action to be taken in relation to an estimated 150 unaccompanied minors in a refugee camp in Calais.
Under European regulations known as Dublin III, child asylum seekers can have their claims transferred to another EU country if they have relatives there.
However, the system has come under fire amid claims the process can take several months.
Charities have identified children as young as ten who have fled war and fighting in countries such as Syria as potentially eligible to travel to the UK under the agreement, according to the commissioner's office.
Ms Longfield said: "I have asked the French authorities to urgently determine which of the children in the Calais refugee camp are eligible to come to the UK, to ensure their safety and to process their applications immediately.
"It is unacceptable that at the moment some are waiting up to nine months before they learn whether or not they can come.
"The camp is an incredibly dangerous place for an unaccompanied child."
She also expressed concern about a failure to find and trace a reported 129 lone children who have gone missing since the French authorities dismantled parts of the camp and moved the inhabitants in early March.
"The charities working with them have tried hard to trace them and the authorities must do likewise," she said.