Devastating floods in North Korea have unleashed a humanitarian crisis that may worsen sharply in the next few weeks, the United Nations World Food Programme said Friday.

It said the flooding not only destroyed tens of thousands of buildings, it wiped out a harvest that was still in the ground.

"Because of the damage to roads and bridges, some of the worst-affected areas have not yet been reached, so they're still at the point when many more people may need assistance in the coming weeks," WFP spokeswoman Silke Buhr said.