"According to figures from the North Korean agriculture ministry, 223,381 hectares of rice, corn, and soja have been damaged, or more than 20 percent of rice crops, and 15 percent of corn fields," said World Food Programme spokeswoman Christiane Berthiaume.

The reclusive communist state had so far reported about 300 people dead or missing after torrential rain earlier this month, 300,000 homeless and 11 percent of the grain harvest -- equivalent to 450,000 tonnes -- lost.

Berthiaume gave no new estimate of the number of homeless in the 92 affected counties or of overall relief aid needs in the country, which was already heavily dependent on WFP food deliveries beforehand.

The WFP has already announced that it will distribute food aid to 215,000 people for three months, in districts where the agency are present and can watch over distribution.

UN agencies are still evaluating the extent of the damage in several counties, and the assessment missions are due to be completed on Sunday, Berthiaume said.

The United Nations has said it is preparing to make an urgent appeal to mainly western donors for relief aid in North Korea.