Flooding in North Korea that has killed hundreds of people is worse than last year's massive floods, officials have told the World Food Programme (WFP).
The flooding follows days of torrential rain in North Korea
North Korea was devastated by seasonal floods in August last year. Hundreds of people are thought to have died, although exact figures are not known.
Heavy rain has swollen rivers, flooding huge areas of farmland and destroying thousands of homes, state media said.
North Korean authorities have asked the WFP, the UN's food agency, for help.
"Our understanding is that the damage is very extensive. It has affected a greater area than the floods of last year," Paul Risley of the World Food Programme told the BBC News website.
North Korea's official news agency KCNA said Kangwon province has been the worst hit, with 20,000 homes damaged.
Television pictures from the capital Pyongyang showed people wading along streets through thigh-deep water after rivers burst their banks.
Michael Dunford of the WFP in Pyongyang said that a team was going to assess the damage, while South Korea was looking into sending aid, Deputy Unification Minister Seo Sung-woo in Seoul said.
Storms since 7 August had led to "huge human and material damage", KCNA said.
Hundreds of persons are dead or missing and more than 30,000 houses have been destroyed across the country, it added.
At least 800 public buildings, more than 540 bridges and sections of railway were reportedly destroyed by the rain.
"This unceasing heavy rain destroyed the nation's major railways, roads and bridges, suspended power supply and cut off the communications network," the agency said.
As well as Kangwon, North Hwanghae and South Hamgyong provinces were also badly affected.
North Korea is secretive about releasing full details of accidents or natural disasters, making any confirmation of the extent of the flooding difficult.
But North Korean officials told the International Federation of Red Cross and Red Crescent Societies that 200 people were dead or missing, acting delegation head Terje Lysholm told the Associated Press news agency.
Experts believe that deforestation has made seasonal flooding in North Korea worse.
Farmers have extended arable land into hills and forests in order to grow more food, removing the foliage that prevents erosion and landslides.
North Korea does not produce enough food to feed its population and is reliant on foreign food aid.
Mr Dunford said that the floods could constitute an extensive disaster for North Korea.
"This is something that will evolve throughout the rest of the growing season, determining exactly how much of the crop and the harvest has been lost," he told the BBC.
"But certainly North Korea is a food insecure country, it produces less food than required, so to lose any of the harvest will be a long-term concern for the North Korean authorities and for the World Food Programme."
About two million people are thought to have died from famine in the mid-1990s in North Korea.