The Duchess is urging parents to seek help for children with emotional difficulties.

The Duchess of Cambridge Kate Middleton has put her weight behind the UK's first Children's Mental Health Week… in her most eloquent way.

Speaking for the charity Place2Be – an organisation providing emotional and therapeutic services in primary and secondary schools – Kate says a child's mental health deserves the same quality of support as their physical health.

In a plea for parents and children to speak openly about mental health, she says parents should be ready to support a child coping with emotional difficulties.

YouTube SURE TO BE HEARD: The Duchess of Cambridge delivers a heartfelt message to parents and children.

"Both William and I have seen that many young people are struggling to cope with the impact of bullying, bereavement, domestic violence, family breakdown and more," she says.

Without support, the effects of these challenges can lead to anxiety, depression, addiction and self-harm, she adds.

On this side of the world, the Mental Health Foundation of NZ says it is encouraged by Kate's support of such an important cause.

"The mental wellbeing of children is of vital importance," said chief executive Judi Clements.