Heavy rains and floods have devastated swathes of North Korea, leaving hundreds of people homeless and severely damaging crops, reports say.
The North's official news agency, KCNA, said at least 100,000 hectares (247,105 acres) of farmland had been washed away by the unusually strong monsoon rains.
It said homes of more than 1,000 families were destroyed in July alone.
Some five million North Koreans depend on foreign food aid, and famine has caused many to flee the country.
"At least 100,000 hectares of paddy and non-paddy fields were submerged or washed away and dwelling houses for more than 1,000 families and public buildings destroyed," KCNA said.
"It is hard to expect any harvest from the fields washed away and silted. Harvest in many fields is expected to drop 30%," the agency added.
It said hundreds of sections of roads and railways were destroyed and communications links affected, without providing any details on casualties.
An estimated quarter of the North Korea's 22 million people depend on food aid from abroad to survive.
Food shortages which periodically trigger famine force thousands of North Koreans to leave their country, mostly via China.
Last week, more than 450 North Korean defectors were airlifted to South Korea from an unnamed third country.
This year the World Food Programme has appealed for 484,000 tons of aid to help feed the most vulnerable North Koreans. But to date it has only received pledges amounting to 125,000 tons.
A fall-off in donations since mid-2002 has forced the programme to halt certain supplementary rations.
But there was one cause for optimism over the weekend. A $10m Russian shipment of wheat arrived in Pyongyang, the first ever Russian donation to the isolated state handled by the World Food Programme.