Human Concern Pledges $3.5M for Gaza Aid
UNICEF estimates 1M Gaza children need mental health support, with 97% of schools damaged.
Gaza's population of 2.1M is predominantly young.
Khan emphasized urgent aid access and education in Gaza.
UNICEF's 97 hubs have reached 111K of 700K school-aged Gaza children.
New hub will distribute food and medicine to 1,500 children.
Israel restricts aid access, while governments demand excessive info.