Professionals working with children in Wales are to be issued with guidance on how to pick up on child trafficking.
Children trafficked in to the UK can end up in prostitution
Figures suggest more than 300 children have been trafficked into the UK since 2004, ending up in, among other things, prostitution and forced labour.
The Welsh Assembly Government says such children are increasingly being brought into Wales by ferry from Ireland.
NSPCC Wales said further measures were needed to "assist the special needs of child victims of trafficking".
The draft guidance is to outline the methods used by traffickers, the possible clues that a child may have been trafficked and the roles and functions of the different agencies responsible for caring for and protecting children.
The assembly government said children were often trafficked through several countries before arriving in the UK, with an increasing trend for children to arrive via smaller airports or in Wales by ferry from Ireland.
It said children were nearly always trafficked for some kind of financial gain, ranging across illegal adoption, begging and forced labour or to be drug mules or prostitutes and even for the removal of their organs.
The advice is to suggest that trafficked youngsters may be unable to confirm the name and address of the person meeting them on arrival, they may not be enrolled in school or they may go missing for periods of time.
The guidance, published on Tuesday, is intended for professionals in children's social services, education, immigration, health and law enforcement.
Speaking on Radio Wales, deputy health minister Gwenda Thomas said agencies needed to have "joined up thinking" on the issue.
She said: "It's becoming clear that child trafficking is on the increase.
"There's just so much of it going on. There are various reasons for it - poverty, the lack of education, (sexual) grooming, dysfunctional families.
A trafficked child may not have details of who they are meeting
"There is some data and evidence that this is happening within the United Kingdom and, of course, some children are trafficked into the UK.
"There are things which can be looked out for: Children might be isolated, they might be travelling with illegal documents. One of the things that struck me was children might have no money but will have a mobile phone."
NSPCC Wales director Greta Thomas said: "We are encouraged that the Welsh Assembly Government is taking action to address the need to safeguard children who may have been trafficked in Wales.
"We look forward to working with the assembly government around this issue and hope that the final guidance will address the wider measures needed to support and assist the special needs of child victims of trafficking."