Some 250 million children -- one in nine children worldwide -- live in countries affected by violent conflicts, UNICEF lamented Tuesday, saying it needed nearly $3.0 billion this year to help the most vulnerable of them.

‘The number of children trapped in humanitarian crisis around the world is both staggering and sobering,’ the UN children's agency said.

UNICEF said it would need a full $2.8 billion (2.6 billion euros) in 2016 to help millions of children in humanitarian emergencies around the world.

The agency said its annual appeal had doubled in just three years as conflicts as well as extreme weather force growing numbers of children from their homes and expose millions more to severe food shortages, violence, disease, abuse and threats to their education.

‘Around one in nine of the world's children is now living in conflict zones,’ the UN agency said in a statement.

This is a devastating number. Last year, children living in such areas ‘were twice as likely to die of mostly preventable causes before they reached the age of five than those in other countries,’ it said.

UNICEF said the money it was asking for in 2016 would allow it to reach 76 million people -- 43 million of them children -- across 63 countries.

By far the biggest chunk of that amount -- nearly $1.2 billion -- is needed for aid in war-ravaged Syria and to help the millions of Syrian refugees in neigbouring countries, it said.

More than 260,000 people have been killed in nearly five years of brutal conflict in Syria, while more than four million people have fled as refugees and some 13.5 million people remaining in the country are in desperate need of humanitarian aid.

UNICEF meanwhile said a full quarter of the aid it wanted to deliver globally was linked to educating children in emergency situations, stressing that it wanted to nearly double the number of children it helps to access education in crisis zones from 4.9 million in 2015 to 8.2 million this year.

‘Education is a life-saving intervention in emergencies,’ UNICEF representative Sikander Khan told reporters in Geneva.

It's been shown, he said, that ‘if a child doesn't go to school for five years, you have lost a generation.’

This does not bode well for Syria, where one in four schools have been destroyed and more than two million children are out of school.

Education does not just entail learning, but also helps provide children with a ‘sense of normalcy and hope for the future in the midst of violence, instability and disaster,’ UNICEF stressed in its appeal.