The Scottish and Welsh governments have written to the UK Immigration Minister raising concerns about the treatment of unaccompanied child refugees.
Scottish Secretary for Communities, Social Security and Equalities, Angela Constance, and her Welsh counterpart Carl Sargeant have sent a joint letter to Brandon Lewis which criticises "lack of planning and sharing of useful information" in the Dubs scheme to resettle the children.
They also backed a recommendation from a recent UK Parliament human trafficking inquiry that the scheme needs to be more open.
Earlier this year it emerged that the programme, which required the Government to resettle an unspecified number of unaccompanied minors from Europe, would close after 480 were brought to the UK - well below the 3,000 campaigners had called for.
The letter states: "From the start of the implementation of this scheme, we have struggled with the lack of information that has been forthcoming from those running this operation.
"This continues to be the case and we are aware that only a couple of hundred unaccompanied children have been transferred of the 480 placements identified."
The letter said Ms Constance and Mr Sargeant are aware the emergency clearance of the Calais refugee camps led to "difficult circumstances" and that the UK Government is awaiting the outcome of a judicial review on the scheme.
Charity Help Refugees is seeking court orders to force Home Secretary Amber Rudd to abandon the 480 children cap and reopen the consultation process so that consideration can be given to allowing more children in.
The letter continues: "However, we both feel that overall, the lack of planning and sharing of useful information from coordinators has inhibited our ability to plan ahead.
"We are seeking assurances from you that steps have been taken or are being put into place to mitigate against a repeat of these circumstances."
The devolved ministers also backed a recommendation from the parliamentary human trafficking inquiry that the Dubs scheme "needs to be open to more children in practice and more children need to be included" including expanding criteria, urgent application processing and teams on the ground in Dunkirk and Calais.
They also highlighted the inquiry finding that no evidence was found to support the assertion that continuing the programme indefinitely will act as a "pull factor" and encourage traffickers.
Instead, the inquiry found that leaving the children without "safe and legal options" put them at greater risk of trafficking.
UK ministers say they are committed to resettling up to 3,000 children and families from the Middle East and North Africa, in addition to the Vulnerable Persons Resettlement Scheme.
Local authorities across the country are currently supporting more than 4,000 unaccompanied asylum seeking children, they said.
Immigration Minister Brandon Lewis said: "We are committed to fulfilling our commitment under the Dubs scheme as soon as possible and ensuring that children arrive in the UK safely. This is just one aspect of a much wider response. We have committed to resettling 23,000 people directly from regions of conflict and last year we granted protection, or another form of leave, to over 8,000 children.
"We are grateful for the support Scotland and Wales have provided and we have made clear our intention to extend the National Transfer Scheme to the rest of the UK so their local authorities can fully participate.
"We believe the most vulnerable children are in the conflict zone around Syria and best way to help them is by resettling refugees directly from the region. This is how we can stop traffickers and smugglers from exploiting vulnerable people and children."