Scythe in hand, a woman slices through a bright green field of rice. Oxen plod down country roads pulling carts piled high with harvested stalks of grain.

This autumn, as farmers fan out into fields of corn, wheat, rice and cabbage, such evocative pastoral scenes -- the stuff of centuries-old Dutch landscape paintings -- also are a reminder of the challenges North Korea faces in feeding its people.

Primitive farming techniques, a lack of arable land in a rugged, mountainous country and the suspected diversion of food to military and ruling party elites have all contributed to widespread hunger in the country's poorest areas, aid groups say.

This year, summer floods, soaring global food prices and the continued reluctance of the U.S. and its allies to provide aid to a hostile and nuclear-armed country means millions of children and pregnant women are slowly starving, aid groups say. So this autumn harvest is being watched particularly closely, and already there are concerns that it won't be nearly enough to feed a nation that has struggled with food shortages for more than 15 years.

North Korea faces a "potentially catastrophic food situation," five charities warned the administrator of the U.S. Agency for International Development in a Sept. 26 letter obtained by The Associated Press, "with clear indications of acute malnutrition and slow starvation -- especially in children."

And a far greater crisis may unfold in six to nine months when stocks run low, said Mercy Corps, Samaritan's Purse, World Vision, Christian Friends of Korea and Global Resource Services after visiting three hard-hit provinces last month.

This week, the top U.N. official for humanitarian affairs, Valerie Amos, is visiting hospitals, schools, orphanages, farms and a food distribution center around the industrial city of Hamhung, northeast of the capital, Pyongyang. "I'm particularly concerned over the reports that there's increasing malnutrition among children," she told AP in Pyongyang.

In the countryside near Wonsan, south of Hamhung, rice plants lie stacked in piles, corncobs dry on the tiles of traditional farm cottages. A woman cradles bundles of Napa cabbage, which will be used to make kimchi, the spicy staple of Korea.

But pull back the husks and you find the corn is stunted, the kernels shriveled. The potatoes are tiny, the greens meager -- the result of the floods that engulfed the region's southern breadbasket.

"You may see a whole field of green rice plants swaying in the breeze -- which we saw a lot of -- but the rains knocked down a lot of the pollination needed at critical times," said Jim White of Mercy Corps. "The rice never properly matured."

It's a humanitarian crisis that threatens to physically and intellectually stunt entire generations of North Koreans subsisting, at times, on just one potato or a fistful of cornmeal a day, aid workers say. Already, a third of North Korean children younger than 5 are chronically malnourished or stunted, according to the World Food Program.

"The child's brain needs protein," said White, who was part of the September group that traveled North Korea. "They need fat. They can't just grow on starches."

He described visiting pediatric wards in the city of Haeju filled with sick, starving children. They lay listless on blankets on the floor, bones protuding from skinny arms, legs jutting out from baggy sweatclothes, lacerations on their discolored, sallow faces. One bout of diarrhea would be enough to kill a child already weakened from years of malnutrition, he said.

"I'm sure there are kids there who are dead now," he said. "They were pretty far gone."

In April, the U.N. appealed to its member nations for $218 million in food aid for North Korea. Six months later, donor nations have coughed up less than a third of that amount, and the question of whether to help feed the North Koreans remains mired in political calculations by governments cautious about offering help to a regime with a history of defiance.

Washington approved $900,000 in emergency flood aid, mostly tents and plastic sheeting, in August. But the Obama administration is still mulling whether to offer food aid, even after sending officials to North Korea to assess the food situation four months ago following a direct plea from Pyongyang in January.

The North Koreans raised the issue of food aid at nuclear talks with the U.S. in New York in July, State Department spokeswoman Victoria Nuland said, and a new round of U.S.-North Korea talks on disarmanent is set to take place next week in Geneva.

The U.S. reluctance to commit to more food aid reflects a familiar dilemma for Washington: whether to help North Korea when its own officials plow scant national resources into developing atomic weapons and ballistic missiles.

Providing aid also risks alienating U.S. ally South Korea, whose president has linked aid to nuclear disarmament and has all but stopped aid and money to Pyongyang following the sinking of a South Korean warship last year that killed 46 sailors.

Michael Green, an analyst at the Center for Strategic and International Studies think tank and an ex-Asia adviser to former President George W. Bush, says the food and nuclear issues should be separate.

"If you don't get satisfaction on the nuclear deal and you don't give food aid, what you're at least implicitly doing is suggesting that the North Korean people should not get food because of the regime's stance on nuclear issues," he said.

Amos sad she hopes to be able to reassure donors that funding for the U.N. appeal will make it to the hungry and not to the plates of the political and military elite. North Korean officials have expressed a willingness to allow rigorous monitoring of aid distribution, White said.

The issue of food aid to North Korea is not new: The nation built on a philosophy of self-reliance was forced to accept outside help during a famine in the mid-1990s that killed hundreds of thousands of people, and to this day grudgingly relies on aid to feed up to a quarter of its population of 24 million.

But the latest crisis comes at a delicate time for Pyongyang.

Next year marks the 100th anniversary of the birth of late President Kim Il Sung, a landmark milestone seen as a key occasion to rally national pride and unity. At the same time, current leader Kim Jong Il is grooming his young son Kim Jong Un to eventually succeed him as ruler.

One of Kim Il Sung's most famous creeds was to ensure that his people eat "rice and meat soup," and filling bellies is one way to ensure loyalty.

Current government policy calls for building up the economy, including modernizing farms. But even North Korea's impressive new showcase farms aren't producing enough to make up for the damage from the harsh winter cold and summer flooding.

In March, the WFP warned that North Korea's publicly distributed rations would run out by July. While that didn't happen, U.N. workers in Pyongyang say rations were reduced to less than 200 grams a day.

Those with cash, especially in Pyongyang, can supplement government-provided rations with meat, fruit and vegetables. Farmers also share their own harvest with relatives in the cities.

But here in the country, and in many of North Korea's poorer small cities, people have neither the cash nor the access to protein, produce or gardens.

Yet these country roads, lined with stone monuments emblazoned with the words for "self-reliance" and "military first," bustle with people hauling corn and rice balanced on their heads, strapped to their bicycles or packed into wooden V-frames. Red flags flutter in the fields to signify that the harvest is under way. Billboards exhort the farmers to work hard and bring in a good harvest.

"Let's carry out the Great President Kim Il Sung's orders thoroughly!" says one.

"Let's build a strong and prosperous nation our way!"