AWEIL, South Sudan (AP) — Two months after the world's youngest nation declared a famine amid its civil war, hunger has become more widespread than expected, aid workers say.

South Sudan's Northern Bahr el Ghazal region is on the brink of starvation, with 290,000 people at risk of dying without sustained food assistance. Humanitarian workers say conditions will only deteriorate as the lean season approaches.

In February, South Sudan and the United Nations formally declared a famine in two counties in Unity State. Northern Bahr el Ghazal's five counties now face the same fate.

"All five counties are sliding into catastrophe," said an aid worker who spoke on condition of anonymity because he was not authorized to speak publicly on the issue. "If it wasn't for food assistance, this place would be at a level five famine."

Northern Bahr el Ghazal and its 1.4 million residents have remained relatively peaceful during South Sudan's three-year civil war. But due to soaring inflation fueled by the conflict, harsh climate conditions and its remoteness, this region has become severely affected by hunger.

"I'm worried that one day I'll die with my children because we can't get food," said Abuk Garang. The young mother stared at her son's emaciated legs while he anxiously tugged at her breasts.

The boy, William Deng, was born in September, yet he looks more like a newborn. Unable to draw any milk, the child chokes back tears and begins gnawing on his fist.

Garang tries to console him, but she knows he's famished.

"We've only eaten leaves for three days," she said. "If there's no food, he'll die."

When Garang heard that food was being distributed in a nearby town, she and thousands of others flocked there in desperation. After hours of waiting, she beamed and pointed to her new bag of sorghum, then shielded her face, embarrassed by her excitement.

One by one, others staggered into aid group World Vision's food distribution compound. Some had hobbled through the bush on one good leg, while others had walked for hours with bloody feet under the sweltering sun.

A steady stream of women with weak children strapped to their backs and babies attempting to nurse could be seen for miles.

World Vision last week rolled out the first phase of a program to provide 65,000 people in Aweil East county with food during the month of April. The aim is to start with 17,000 of the most severely malnourished and vulnerable people.

Aid workers said they weren't prepared for the level of despair.

"I was shocked by the number of malnourished kids here," said the aid group's South Sudan communications manager, Rose Ogola. "And the looks of desperation on the mothers."

In the small town of Malualkuel alone, where the food was distributed, local leaders said 4,000 out of the town's 6,000 people are facing extreme starvation.

"It's the worst I've ever seen it in 12 years in terms of food security and hunger-related deaths," said James Maywien Aror, Aweil East county's relief and rehabilitation commissioner. "I feel sad. I'm not happy to see people die."

During a food and security review meeting last week in Aweil town, aid workers and government officials estimated an increase of 3 to 5 percent in the number of people in Northern Bahr el Ghazal who will face extreme hunger in the coming months.

"The region requires sustained humanitarian support," said George Fominyen, spokesman for the World Food Program in South Sudan. "Without that, and without the improvement in the conditions of people there, you're going to find those with the threat of moving into phase five." Level five in global food security classification is famine.

The U.N.'s refugee agency said Tuesday the "risk of mass deaths from starvation" is growing in South Sudan.

With the onset of the lean season in June and July, the fear is there won't be enough food to meet the growing demand. Local community leaders said 200,000 metric tons of food is still needed for Northern Bahr el Ghazal.

"Yesterday we didn't eat anything at all," said 20-year-old Adel Bol. Like so many others, she had heard there was food and quickly came running.

Cradling her 10-month-old daughter, she lifted the baby's shirt to reveal her protruding ribs. Akir Mayen's bald head is twice the size of her skeletal body. She flailed her arms, trying to clutch at her mother's chest.

"If she dies," Bol said, "I'll never give birth again."