A severe shortage of trucks has created a backlog of famine-relief food at Ethiopia's ports and warehouses, caused food at many feeding centers to fall short and threatened to undermine an international effort that is now pouring in more than 100,000 tons of food monthly.

Fearing that food would spoil on the docks of Ethiopia's ports, Kurt Jansson, United Nations assistant secretary general for emergency operations in Ethiopia, threatened this month to postpone scheduled food shipments unless the truck shortage was resolved.

The government responded today by promising to divert 200 trucks to the main port at Assab, where Jansson said 65,800 tons of food are waiting on the docks and another 137,500 tons will be arriving on ships due within the next month.

Even with this diversion, "there are just not enough trucks in this country," according to Roman Roos, chief transportation official for the U.N. emergency operation in Ethiopia. He plans to make an urgent appeal next week at a meeting here of international donors for 450 long-haul trucks, worth $33.5 million.

The shortage of trucks to haul famine-relief food has been exacerbated, according to relief officials, by the need to divert trucks to carry seed and fertilizer to the 3 million or so famine-affected Ethiopians who have not abandoned their farms yet.

Relief officials say trucks have also been diverted to assist in the Ethiopian government's resettlement effort, which in five months has moved more than 330,000 people from the central highlands to lowlands in the southwest.

In this country, which is twice the size of France and is scarred by some of the world's most inaccessible terrain, the government estimates that famine affecting 7.7 million people has created a need this year for 1.3 million tons of emergency food.

Management of the food delivery is straining Ethiopia's transportation bureaucracy, western relief officials say.

"There is simply no effective reporting system for what the requirements are throughout the 225 or so feeding centers," said a senior western aid official.

According to Jansson, the timing of food deliveries is as important as the equipment needed to deliver it. "We have people who haven't yet abandoned their farms, who each month walk or come by donkey to a distribution center to pick up a ration of food. If there is food when they arrive, they can return home," Jansson said.

He added that the coming of the rainy season in June will make many famine-stricken regions inaccessible.

Management of the flow of aid has deteriorated since large shipments began arriving here in January, according to U.N. and other aid officials. They say this is partly the result of a power struggle within the Marxist military leadership, between the increasingly powerful Workers' Party of Ethiopia and the quasi-independent Relief and Rehabilitation Commission.

According to senior western aid officials, party leaders in rural areas have in recent months overruled the commission's distribution decisions, in some cases diverting food and trucks from feeding centers in the north to resettlemnt camps in the south.

Western donors, particularly the United States, have opposed the resettlement plan, charging that Ethiopia is ill-prepared to feed, house and provide medical care for the 1.5 million people the government says it will move by the end of this year.

In countries such as Ethiopia, which have not compensated Americans for nationalized property, U.S. law proscribes the spending of aid money on projects deemed "developmental." According to U.S. officials here, buying trucks is developmental.