Under the terms of the proposal, the centre would provide reintegration assistance in Afghanistan for around 12 boys aged 16 and 17, and 120 adults, per month.
A number of other European countries, including Sweden, Denmark and the Netherlands, are planning to return children to care centres in Afghanistan while Norway says it will build a similar facility in Kabul.
The moves are supported by an EU policy that says child asylum seekers can only be deported if reception centres are created to care for minors when the family cannot be found.
But Donna Covey, chief executive of the Refugee Council, said the plans did not say how children would be kept safe once back in Afghanistan.
"It really begs the question: if they have no family to whom they can be returned safely, should they be returned at all?"
"EU member states are willing to override safety concerns and children's interests in order to rid themselves of responsibilities generated by migrant children"
Human Rights Watch
"There are serious questions to be raised about the quality of decision-making on the cases of unaccompanied children.
"The money would be better spent improving the way that children's claims are assessed, so that we can be sure we never put them in danger," she said.
Caroline Slocock, chief executive of Refugee and Migrant Justice, said that children had often endured long and dangerous journeys to Britain, and sending them back to Kabul would only put "their safety and welfare further at risk".
Human Rights Watch has challenged the decision, writing to the Norwegian government earlier this year about what procedural guarantees it will provide to ensure a child's return is in his or her best interests.
"Returning migrant children to their country of origin just won't work for every child, Simone Troller, a researcher at the agency, said.
"Recent government statements confirm our fears that EU member states are willing to override safety concerns and children's interests in order to rid themselves of responsibilities generated by migrant children in Europe," she said.
Many Afghan asylum seekers arrive in Britain via smuggling channels and overland journeys on trucks, Peter Kessler from UNHCR, the UN refugee agency, told Al Jazeera.
According to Britain's home office there are approximately 4,200 unaccompanied child asylum seekers in the country, with those from Afghanistan making up the largest group.
Damian Green, the UK's immigration minister, said the proposed centre was part of a policy to discourage Afghans from making "dangerous journeys across the world".
"We are looking to work with other European countries, such as Norway, and valued international partners, such as Unicef, as well as the Afghan government to find ways to help these young men in their home countries and to return those who are in the UK safely to their home nations with appropriate support once they arrive," he said.
The decision could mark a change in British policy, with the number of deportations previously limited due to child protection issues and care arrangements for minors.