Nepal, India and Bangladesh have been hit by flooding and mudslides after torrential monsoon rains
The UN says at least 45 million people - including 16 million children - are estimated to have been affected by heavy flooding in parts of South Asia.
Nepal, India and Bangladesh have been hit by torrential rain and intense flooding in recent weeks, with the monsoon season expected to last for several weeks yet.
Almost 1,300 people are believed to have died since mid-August as a result of flooding and landslides.
According to the UN's children agency UNICEF, 31 million people have been affected in northern India, with 8 million affected in Bangladesh.
Jean Gough, UNICEF Regional Director for South Asia, said millions of children have seen 'their lives swept away'.
She said: "Children have lost their homes, schools and even friends and loved ones. There is a danger the worst could still be to come as rains continue and flood waters move south.
"Getting children back into school is absolutely critical in establishing a sense of stability for children during times of crisis and provides a sense of normality when everything else is being turned upside down," she suggested.
UN Secretary-General António Guterres yesterday pledged his organisation's support for relief efforts in the region.
He also extended his condolences to the governments and people of Bangladesh, India and Nepal, stating that he "salutes the respective Governments’ leadership in responding to the needs of those affected".