UN staff visited storm-pounded counties in the Democratic People's Republic of Korea on Tuesday, after two days of heavy rain submerged buildings, cut off power, flooded rice paddies and forced people and their livestock to climb onto rooftops for safety.

The rain on Sunday and Monday followed downpours earlier this month that killed nearly 90 people and left more than 60,000 homeless, officials said. The floods also come on the heels of a severe drought, fueling renewed food worries about a country that has problems in feeding its people.

Two-thirds of the DPRK's 24 million people face chronic food shortages, a UN report said last month, while asking donors for $198 million in humanitarian aid for the country. Republic of Korea's analyst Kwon Tae-jin said the recent flooding, coming so soon after the dry spell, was likely to worsen the DPRK's food problems.

Pyongyang-based United Nations staff have sent two teams, which were visiting hard-hit South Pyongan province in the west of the country and another for Kangwon province in the east, to "see what help if any the UN country team can provide", Christopher de Bono, UNICEF's chief of communications for East Asia and the Pacific, said on Tuesday. He had no other details.

The flooding represents a challenge for Kim Jong-un, new leader of a country which has grappled with severe food shortages since a famine in the 1990s, AFP said.

Francis Markus, a spokesman for the International Federation of Red Cross East Asia, said in Beijing that his fact-finding teams in the DPRK are reporting that drinking water, food and shelter are all critically needed.

"Drinking water is a critical issue with the water systems having been taken out of action, and there's obviously a danger of water-borne diseases if things are not done to improve the situation," he said.

On Sunday and Monday, rain hit the capital, Pyongyang, and other regions, with western coastal areas reporting heavy damage.