Increasing quantities of U.S. emergency food aid are going to famine victims in contested war zones of far northern Ethiopia, but a backlog of supplies at the main Ethiopian port of Assab threatens the relief operation, according to officials of the Agency for International Development.

Two private U.S. relief agencies are distributing food to 150,000 famine-afflicted peasants at seven centers in the war-torn northern province of Eritrea as part of the U.S. "Food for the North Initiative," AID Administrator M. Peter McPherson reported Friday.

The objective of the operation's first phase has been to reach 300,000 victims and open 13 feeding centers in areas contested by guerrillas seeking Eritrean independence.

For a long time, the Ethiopian government was reluctant to allow the two U.S. relief groups, Catholic Relief Services and World Vision, to operate in or near Eritrean war zones. AID was involved for months in negotiations with Ethiopian authorities to allow food to be distributed there.

Now, the operation is threatened by a backup at Assab on the Red Sea of emergency U.S. food waiting to be unloaded from ships in the harbor or moved inland from the docks, according to McPherson.

A total of 112,000 tons of famine relief supplies is bottled up inside the port, and another 40,000 tons is waiting aboard ships.

"The whole thing is becoming a matter of concern to us," McPherson said in an interview. "The other donors are concerned about it, too."

Ethiopian handlers are moving food from the port at the rate of about 2,000 tons a day, but McPherson said about 3,000 to 3,500 tons daily is required "at the absolute minimum" to prevent serious spoilage of supplies, much of which have been in Assab for several months or more.

The United States provided 440,000 tons of emergency food relief to Ethiopia in the last fiscal year, one-third of total Western donor aid. McPherson said no decision has been made on the amount to be supplied to Ethiopia during this fiscal year because the size of the harvest there is unknown.

He warned, however, that the drought, which reportedly claimed more than 200,000 lives last year, has not ended and that "hundreds of thousands of tons" would probably be necessary again during the current fiscal year.

Meanwhile, 75 of 150 tractors and 138 of 200 trailers provided by AID and capable of hauling 40 to 60 tons of food each have arrived in Ethiopia to be used principally to move food from Assab to northern Ethiopia.