News of the natural disaster came as North Korea looked even more isolated from its neighbours and the wider world after its fifth nuclear test last Friday.

The U.N. Office for the Coordination of Humanitarian Affairs (OCHA) said in a report more than 35,500 homes were damaged, two-thirds of them completely destroyed, and 107,000 people had been displaced by the floods.

The agency said the death toll and the number of missing people were based on North Korean government data.

North Korea's state media reported heavy rain in late August and early September caused extensive damage near the Tumen river. It did not give a death toll from the flooding in its latest report.

The U.N. office said damage assessment was based on a visit to the region last week by representatives of U.N. agencies, the International Federation of Red Cross and Red Crescent Societies, the North's Red Cross chapter and non-governmental groups.

The North's KCNA news agency said on Sunday the worst "climatic phenomenon" in more than 70 years hit the northern part of the country causing "huge losses," and recovery work was under way.

Widespread deforestation for fuel and farming makes the impoverished state prone to natural disasters, especially floods.