After a third dismal harvest in as many years, North Korea expects to run through its domestic food stocks by April, leaving it reliant on foreign aid, a relief worker said Wednesday.

Dependence on food aid also comes as the transportation system needed to deliver relief is on the verge of collapse for lack of fuel and spare parts.A mild winter made it easier for hungry North Koreans to stay warm, but the lack of snow, coming after a severe summer drought, will mean water shortages later, said Kathi Zellweger of Caritas, who returned Tuesday from a trip to the country.

"The lean period is still ahead of us," said Zellweger, the charity's Hong Kong director. "From speaking to the local officials, there was a fear that it may be even earlier than April."

Last year, North Korea also depleted its grain stocks in the spring, leaving it dependent on donations and purchases from abroad, and forcing its people to scavenge for seaweed, grass and anything else that could be eaten.

Flooding and drought have combined with years of mismanagement in North Korea's centrally planned communist economy to push the country to the brink of starvation. According to Chinese news reports, the autumn harvest produced only 60 percent of the minimum amount of grain needed to feed the country's 24 million people.

Zellweger, who has visited North Korea 15 times over the past three years, said thanks to massive foreign aid, hunger didn't appear to be any worse than during her last visit in November.

"We did not see severe or widespread malnutrition in the general population but there are still malnourished children in institutions," she said.

Magnifying the impact of the famine has been an economic collapse brought on by the loss of Soviet bloc aid and trade. Factories are idle, hospitals have no drugs, most homes are unheated and visitors report seeing no vehicles on the roads.