Councils outside of Kent are being asked by the government to "take responsibility" for lone migrant children arriving via the Channel.
More than 48 councils have pledged at least 200 places since June, but the Home Office says more are needed.
It comes after Kent County Council said the authority's resources are under "impossible strain" and it was unable to "safely accommodate" any more children.
Earlier this week, Kent County Council Leader, Roger Gough said the authority was unable to accept new arrivals of unaccompanied asylum-seeking children saying the council cannot "safely meet" its "statutory duty".
The government said the situation was "unprecedented" and said that the authority is being given "significant increases in funding" and support.
Children are being left with Border Force officers at a processing centre in Dover while arrangements are made with social services.
The Kent Intake Unit is a temporary housing facility for migrants who have arrived across the Channel.
Children can only be detained there for 24 hours by law and the Home Office said they are "held for as short a time as possible".