Ministers have been accused of "turning their backs" on lone child refugees who have reached Europe, ahead of a Government announcement on the issue.
Immigration Minister James Brokenshire has indicated that Britain will provide resources to identify children in Greece and Italy who have family members in this country. A new £10 million fund is also being established to support young refugees in Europe.
However, the move is likely to fall far short of demands for the UK to accept 3,000 of the lone children who have arrived in the continent from conflict zones such as Syria.
Instead the Government is set to maintain its policy of taking vulnerable refugees directly from the conflict region in order to avoid creating a "magnet" for more to make the perilous journey to Europe.
In a statement ahead of the announcement later, Mr Brokenshire said: "The crisis in Syria and events in the Middle East, North Africa and beyond has separated a large number of refugee children from their families.
"The vast majority are better off staying in the region so they can be reunited with surviving family members. So we have asked the UNHCR to identify the exceptional cases where a child's best interests are served by resettlement to the UK and help us to bring them here."
Additional resources will be provided to the European Asylum Support Office to help Greece and Italy identify migrants - including children - who could be reunited with family members elsewhere in Europe, including in the UK.
Kirsty McNeill, campaigns director at Save the Children, said there was currently "confusion" around exactly what the Government was proposing.
"What is new is there does seem to be action in Italy and Greece to help the authorities identify more children who are already in Europe and get them to safety here in the UK," she told the BBC Radio 4 Today programme.
However, she said it appeared they would only be eligible if they had a "family connection".
She said the Government had previously been "resisting" the idea that "we do have a responsibility to children that are already in Europe, not just in the region".
Ministers have been under increasing pressure to expand the UK's response to the migrant crisis in Europe, triggered by hundreds of thousands of people fleeing conflicts such as in Syria and Libya.
Labour has suggested some people should be allowed into the country from makeshift camps in Calais, and condemned Prime Minister David Cameron for dismissing the groups on Wednesday as a "bunch of migrants".
The UK has allocated more than £1 billion in aid to the region around Syria and Iraq, and is taking 20,000 refugees from the area by 2020.
But the Government argues that most of those displaced are better served by remaining in the region.
Liberal Democrat leader Tim Farron told ITV's Good Morning Britain that he did not think Mr Cameron had visited any of the camps housing child refugees in Europe.
"The notion that this is going to somehow encourage people to make the journey is untrue," he said.
"It is not only inhuman, it is also very foolish. When you've got a massive humanitarian crisis on your doorstep, to turn your back on it and pretend it isn't happening is very bad politics as well as not being very human."