Mr De Groot - who was interviewed on ABC radio - said many countries such as Afghanistan and East Timor would come under extraordinary pressure if the food program was reduced.
"Then you end up unfortunately with the potential of conflict for basic resources within countries," Mr de Groot said.
The UN says it is considering scaling back its assistance to poor countries because of rising world food costs. New figures from the UN show food prices rose 40 per cent last year and the program says its budget is increasing by several million dollars each week.
Mr de Groot added unpredictable weather patterns are also having an impact on food shortages.
"When we had the south Asian floods in the middle of 2007, we saw 40 million people affected at the time, but what we now see is the ongoing ramifications of that, of food supplies that should have been planted at that time, not being able to be harvested because of damage to land and crops," he said.
"We're starting to see countries where there is real struggle over food security each year. In East Timor, for example, there is always a food security problem in the months of November to February."
Mr de Groot said developing countries need help to create sustainable farming practices to grow their own crops rather than rely on expensive imports.
UN considers scaling back food program (ABC radio 27/02/08)