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.

The aid agency said it has delivered emergency food supplies to 140,000 people in affected areas, but the rations may only delay the likely onset of hunger.

“They’ve lost their homes; many have lost crops and livestock as well,” Buhr said.

Heavy rain in late August and Typhoon Lionrock in September unleashed flooding that destroyed swaths of urban and rural land, particularly along the Tuman River in the north, North Korea’s state media said Wednesday.

“Tens of thousands of dwelling houses and public buildings collapsed, (and the) traffic network and power supply system and cultivated land were submerged or destroyed, inflicting great pain and hardship on the inhabitants,” the Korean Central News Agency reported.

State television called it the worst disaster since 1945.

Relief work is urgent, as the North typically suffers harsh winters.

The WFP said the distributed food came from stocks in factories that had been intended for young children and pregnant and nursing mothers.

While the whole nation suffers high levels of malnutrition, the two provinces affected by the flooding are the worst for food insecurity, WFP said.

Experts say the nation is particularly vulnerable to flooding because hillsides have been stripped of vegetation for fuel.

Floods and droughts in the 1990s resulted in a famine that may have killed hundreds of thousands of people.

Meanwhile, the United Nations Security Council was due to meet later Friday to discuss new sanctions on Pyongyang for the nuclear test it conducted a week ago.

China, North Korea’s main ally, is prepared to endorse harsher penalties, Beijing’s foreign ministry said Tuesday.

However, the Security Council took three months to agree on a package of sanctions after the North’s nuclear test in January.