TOKYO (AP) — About 20 percent of North Korean children are stunted because of malnutrition, and half the children in rural areas are drinking unsafe water, a senior U.N. official visiting the country said.

Much progress has been made compared with 20 years ago, but "significant humanitarian challenges" remain, Mark Lowcock, the undersecretary general for humanitarian affairs, said Wednesday at a news conference in Pyongyang, the capital of North Korea. The U.N. issued a transcript of his remarks.

The United Nations is trying to raise $111 million to meet health, water and sanitation and food s...