SEOUL Shortages of food, energy, clean water and other necessities continue to haunt in North Korea, Unicef said on Wednesday.

North Korea has been depending on foreign aid to feed its 22.5 million people since the mid-1990s as the end of subsidies from former Communist allies and years of bad weather ravaged its state-run economy.

The situation has worsened since the North Korean government admitted in 2002 to pursuing a nuclear weapons program that violated international agreements. That admission prompted the United States and its allies to halt shipments of free oil.

"Energy is a key factor in the decline of social services," Unicef's executive director, Carol Bellamy, said at a news conference in Seoul after a three-day tour of North Korea.

About 70,000 North Korean children are thought to be suffering from severe malnutrition, while there is a shortage of medicine amid deteriorating quality of hospital care, Bellamy said. Humanitarian aid for children is still not reaching 15 percent of North Korea's population, she added, declining to elaborate on the reasons.

After last-minute contributions last month, the United Nations World Food Program resumed shipments of food to North Korea after a shortage of supplies prompted a cutoff in such aid for weeks to more than six million needy North Koreans. But more food aid would be needed in coming weeks the World Food Program has warned.

But since the latter half of the 1990s, there has been progress in areas like immunization as regions in the country became more open to aid from the organization, Bellamy said.

The supply of clean water, which is dependent on power supply, has remained a major problem.

"There is a lot of water in the North, but they don't have the capacity to get that to many people because their electricity system is not working," said Bellamy, who has headed the United Nations Children's Fund since 1995.

A lack of clean water not only causes diseases but also prevents many hungry people from mixing fortified foods, she said.

In most provincial towns, water is available only two to four hours a day, and of poor quality, according to Unicef.

For now, Unicef is turning to gravity-driven water systems to deal with the energy shortage in 3 out of 206 counties. These systems do not require electricity or other power sources, since they use pipes to get water to flow down from mountains.

In an encouraging sign of greater openness by North Korea, Jaap Doek, who heads the United Nations Committee on the Rights of the Child, is scheduled to visit North Korea in April, Bellamy said.

The committee, based in Geneva, regularly monitors the performance of signatory states in meeting their obligations under a UN convention on children's rights. North Korea has signed the convention. "It's the most internationally ratified treaty," Bellamy said. "Under it, you have responsibilities. They're signs of a willingness to be open.

The United States has been preparing for annual joint military exercises with South Korea. North Korea has denounced previous exercises as preparations by the United States to invade the North.

"The Korean people, who consider independence to be their life and soul, are keeping a close eye on the U.S. moves, while further strengthening the self-defense nuclear deterrent to cope with them," said KCNA, the North Korean government press agency.