Famine has already started in the northeastern part of North Korea, he said in a presentation at the U.S.-Korea Institute here.
There are signs that it will quickly spread, he said. These include inflation in food prices, with rice now costing nearly double, people desperate to sell off their belongings at markets, and children missing school or astray in the streets.
"All the attention has been focused on North Korea's security issues, the denuclearization talks," he said, "but in the meantime, the conditions of people's lives have deteriorated."
While South Korea's assistance helped to mitigate the situation until summer last year, North Korea's missile and nuclear tests since then led to its suspension, and international aid virtually stopped, Ven. Pomnyun said.
And yet, the discontent over the food crisis has not yet become a political issue in the North, which still appears to maintain political and military stability, he said. In the meantime, the number of defectors fleeing the North has visibly decreased to almost none because of the strengthened border patrol, he said.
Breaking its customary silence on internal problems, Pyongyang last month publicly admitted to massive damages from record-breaking rainfall and appealed for outside help. U.N. relief agencies and foreign governments have since pledged humanitarian assistance, including the United States.
But Ven. Pomnyon said North Korea has yet to accept the international monitoring requirement for aid, imposing a stumbling block to getting the needed assistance.
He was skeptical that North Korea's economic plight would be cured until the nuclear issue is resolved.
"The U.S. sanctions will continue until the nuclear situation is eliminated," he said. "Under such circumstances, the economic problems will not be solved...Outside assistance would give only temporary relief."