Over 100,000 people have been displaced in the area along the flood-ravaged Tumen River.
The death toll from severe flooding in a North Korean border region has risen to 133 with another 395 missing and tens of thousands left homeless, the United Nations said Monday, citing Pyongyang government officials.
It added that some 107,000 people have been forced to flee their homes in the area along the Tumen River.
The floods come after Pyongyang carried out its biggest nuclear test on Friday. The force of the blast was at least 10 kilotons. The test triggered an artificial earthquake with a magnitude of 5.3, near the country's main nuclear site in north east.
North Korean media said the northeastern region which borders China and Russia were worst hit.
More than 35,500 houses and 8,700 public buildings were damaged, the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) said.
Farm areas have also been destroyed by the heavy rainfall and about 16,000 hectares (39,540 acres) of land is now under water.
OCHA said aid agencies have provided food, shelter, kitchen kits, heath supplies and water purification products to those affected.
Pyongyang was working to reopen roads. The government was also distributing materials to rebuild 20,000 homes by October, before the bitter Korean winter sets in.