Officials at the United Nations Children's Fund (UNICEF) fear up to 2.5 million youngsters could be caught up in the humanitarian crisis gripping the Asian nation after snowfall covered campsites and rainstorms flooded tents.
As temperatures plummet, many youngsters are forced to survive without blankets or socks, and McGregor is backing UNICEF's call for urgent funds to provide protection for the children.
The Trainspotting actor, a UNICEF Ambassador, has filmed a new public service announcement (PSA) which will be broadcast on several U.K. TV networks on Wednesday (30Jan13).
In the clip, he says, "After months of violence living in fear for their lives, the traumatised families were forced to flee for safety with nothing but their clothes they were wearing. But now these children face a new crisis. Heavy winter rain has flooded thousands of tents destroying the only place they can call home. Children have been facing freezing temperatures and fierce winds with no shelter or blankets. They are bitterly cold and frightened."
Millions of families in Syria fled their homes to escape the civil war which has raged since 2011 in the wake of the 'Arab Spring' uprising against President Bashar al-Assad.