GENEVA - The U.N. refugee agency warns humanitarian needs in Afghanistan are rising to epic proportions as winter sets in and millions of Afghans face a crisis of hunger and starvation.

Temperatures in Afghanistan are beginning to plunge below freezing and are expected to drop to minus 25 degrees Celsius. The U.N. refugee agency warns some 3.5 million Afghans forcibly displaced by conflict and war are ill-prepared to survive the bitter cold.

UNHCR spokesman Babar Baloch says many displaced families lack insulated shelters, warm clothes, and fuel for heating. He says they do not have enough food and they lack medical supplies and other essential relief.

"The humanitarian crisis is escalating daily in Afghanistan. Hunger in the country has reached truly unprecedented levels. Nearly 23 million people-that is 55 percent of the population-are facing extreme levels of hunger, and nearly nine million of them are at risk of famine," Baloch says.

He recently returned from a lengthy stay in Afghanistan. While there, he says he witnessed heartbreaking scenes of destitution and desperation.

The U.N. spokesman says he has met single mothers with no shelter or food for their children. He says he has met elderly people who have been displaced and are left to take care of orphaned grandchildren. "One single mother that I met, she has a six-month-old baby, a 12-year-old son, a 10-year-old daughter, and two parents to look after because the husband died in the fighting. So, she has to take care of the full family...Her children go hungry. So, the two kids, the 12-year-old and the 10-year-old-they have to work."

Baloch says malnutrition levels are soaring, with many children ending up in hospitals. He says the condition of some three million malnourished children is very concerning. He warns one million of those children are at imminent risk of dying if they do not urgently receive the support they need.

This year, the UNHCR has assisted some 700,000 displaced Afghans across the country. It currently is reaching nearly 60,000 people every week. Baloch says the race is on to reach more before the winter snows cut off access to many.

He says further support is urgently needed for the UNHCR to continue delivering lifesaving aid this winter and throughout the coming year. The funding needs for this ongoing humanitarian operation, he says, amount to nearly $375 million.