Transcript for Four countries are on the brink of famine

We turn this evening to the urgent warning now that four countries are on the brink of famine. 20 million people, families and children. The doctors are in a race against time as we raffle with the American woman who runs save the children. You're about to see what we wbsed in Somalia land. In northern Somalia as millions face starvation across the horn of Africa. Reporter: We set out to reach some of the most remote villages in somaliland. There is an urgent crisis unfolding largely unnoticed by the rest of the world, families and children at risk of starvation. In the first village, harashef, the line begins early in the morning. They know the trucks are coming. So how many hours away? That would be two hours to get here today. Reporter: Here it's not just the food they need, but water. Save the children is trucking it in. It has not rained here in three years, in some places in four years. Reporter: Halima, a mother of five, stands in line. All of her livestock is gone. They have no food. We ask the last time, there was any rain? She remembers the day. It happened once, last year. On the hill, sit two trucks to deliver water for hundreds of families. If you look over my shoulder, here, you'll actually see that this is what it's like as these families come here every single day to get water. We witness a rush of families, trying to get to the hoses that will give them enough water to last just a couple of days. We journey from west to east. 70% of the livestock, the farm animals, have died. It's really everywhere you look. This mother is among the many, she had 200 goats. There are just 10 left. And this is now her home. She shows us where she sleeps with her children. Five sleep here. Her days are spent worrying about food. She worries every day. She is the mother and the father. Reporter: As we journey deeper into the desert, we see evidence starvation has set in. They are on the brink of famine here. April is supposed to be the wettest month but as you can see it's bone dry. 200,000 children are at risk of starvation. Our first hospital the urgent effort to keep the children alive. The little boy being weighed, his eyes filled with fear. And there was hamda, nearly two years old, she's been here 18 days, and still weighs just 11 pounds, half what she is supposed to. The hunger breaking her immune system, she has pneumonia. The nurse tells us that hamda was so weak, she wouldn't survive another 10 minutes. More than 100 miles away, we arrive at a hospital in burao, where we are told there aren't enough beds. The moment we walk in, we see it. This little girl is 2 years old. Her eyes hollowed. Dr. Yusef Ali is on the frontlines. These are the lucky ones who make it to the hospital, but there are so many kids who didn't make it to the hospital. Reporter: He tells us many children have already died. You believe you're on the verge of famine. That's what I believe. That's what I believe. You're seeing it. We're seeing it here. I don't need a witness to prove it because you can see these patients all over here who are malnourished. Most of the kids do not make it to the hospital. Reporter: Even this boy who's now here is still losing weight. He's in critical condition, Reporter: Suffering from severe diarrhea brought on by the hunger. You can see the bones. You can see the flesh on the bones. Reporter: The doctor says there are no@promises. He's still in critical condition, and we don't know if he's going to make it or not. Reporter: There was Samira, almost two, though her tiny frame says otherwise. Four days in a row, she's lost weight, the hunger breaking down her defenses. She had measles, and now pneumonia. And in this hospital where you hear the cries of the babies, equally as haunting is the silence from the toddlers. Osman has lost the strength to talk. He cannot talk? He hasn't been talking? The images on the walls here do not distract from the truth. They are running out of time. You think you're losing those children? We are losing them. We are losing them. Reporter: Aware of that reality, we travel with the American who runs save the children, Carolyn miles another hour east. Where they are now sending out mobile clinics to isolated villages deep in the desert, we find a little boy so weak he cannot stand. They put a band on his arm, the red signaling severe malnutrition. It's one of the worst crises that we've seen since World War II. Are you concerned that the world does not recognize what is happening here? You know, I don't think the world has really woken up to this disaster at this point. They haven't realized what's happening. The possibility of four famines at once? The possibility of four famines at once. Reporter: As the children are weighed, parents here are given plumpy nut, the packet of nutrients, that in the early stages, can bring a child back. And in a brief escape, we see the smiles here, when we show some of the children, their own faces, in the phone. A rare moment of joy, in a region crushed by hunger. That boy with the band now sent off for emergency care, the next wave of children right behind him. So many of you have already been tweeting me, writing to us on Facebook asking how you can help. Save the children points out the plumpy nut costs about 50 cents. $10 for feed a child for more than a week. Learn much more on the "World news tonight" Facebook page. Much more of our journey tonight, on "Nightline."

This transcript has been automatically generated and may not be 100% accurate.