The reconciliation center said earlier in the day that over 6,000 people, including some 3,000 militants, had left eastern Aleppo for the Idlib province in several convoys in the first 24 hours of the evacuation operation, which kicked off on Thursday.
"More than 2,700 children have been evacuated from east Aleppo in the past 24 hours, including some who were sick, wounded or without their parents," Lake stated. "However, hundreds of other vulnerable children, including orphans, remain trapped inside that part of the city."
Lake said that the trapped children are facing dire consequences if not immediately evacuated.
"UNICEF and our partners are on standby with transport and teams to evacuate these children to safety. We implore all parties to the conflict to let us do so safely and immediately," he added.