Record downpours and flooding in North Korea have left more than 300 people dead or missing, an international aid group said Friday, as South Korea and the U.S. pledged emergency relief assistance.

The number of casualties compiled by the International Federation of Red Cross and Red Crescent Societies — 221 deaths and 82 missing — is much higher than what the United Nations has reported. The U.N. said Thursday that 83 people were killed and about 60 people missing. North Korea has said that hundreds were killed, without providing specific figures.

The United Nations warned Friday that that the food supply situation in North Korea is likely to deteriorate because of flood damage to rice and corn fields.

The Rome-based Food and Agriculture Organization said preliminary estimates indicate that some 11 percent of the area planted with rice and corn has been submerged or washed away.

Rough estimates also indicate that up to 300,000 tons of cereals may have been lost to floods, it said.

The final harvest will depend on weather conditions in the next few months, it said.

Terje Lysholm, acting delegation head of the International Red Cross in Pyongyang, told The Associated Press that the total death toll from the storms would likely end up around 300. There were a number of children among the dead, he said.

The floods damaged more than 80,000 homes, affecting some 350,000 people, Lysholm said.

"We have difficulties accessing these areas because the roads are gone," he said.

Still, the International Red Cross has been able to deliver emergency supplies including kitchen sets, blankets and water purification tablets.

South Korea unveiled a $7.5 million emergency aid package Friday and said it hoped to start shipping the supplies early next week, including instant noodles, drinking water, blankets and medicine.

Leaders of the two Koreas are to meet in Pyongyang later this month for only the second summit since the peninsula was divided, with aid expected to be a key topic of discussion.

The impoverished North has relied on outside handouts to feed its 23 million people since mismanagement and natural disasters devastated its economy in the mid-1990s.

Washington pledged $100,000 to help flood victims. The U.S. had previously been a large source of aid to the North, but has recently scaled back donations after Pyongyang restricted monitoring of relief deliveries.