In a visit that could affect the fate of a million refugees and two civil wars in the Horn of Africa, a high-level delegation from the military government of Sudan arrived here today for meetings with Ethiopia's leaders.

Two members of the ruling military council and Sudan's commissioner for refugees came to Ethiopia to discuss possible repatriation of some of the estimated 1 million Ethiopians who have fled the drought-stricken north during the past 18 months and walked to Sudan.

A Sudanese diplomat here said the delegation also will talk to Ethiopian officials about the northern Ethiopian province of Eritrea, where rebels have been fighting the government for 24 years, and about southern Sudan, controlled by a two-year-old rebel movement.

These civil wars, which are draining the economies of both Ethiopia and Sudan, have soured relations between the two countries. Ethiopia has funded and allowed its territory to be used as a base for the Sudan People's Liberation Army. At the same time, Sudan has allowed members of the Eritrean People's Liberation Front to operate inside its borders.

The Sudanese delegation had paid a visit earlier this week to Libya, which also funds the rebels who resumed fighting last week in southern Sudan. The visits are part of an effort by Sudan's new military leader, Gen. Abdel Rahman Sawar-Dhahab, to mend fences with two key neighbors.

At the airport here this morning, members of the Sudanese delegation were met on the runway and hugged by four senior Ethiopian officials, including Foreign Minister Goshu Wolde. They are expected to meet tonight with Ethiopia's top leader, Mengistu Haile Mariam.

The arrival of the Sudanese officials, which diplomats here said was the highest level contact between the two countries since 1980, followed an Ethiopian proposal last week for a possible resolution of the refugee problem straining Sudan's wobbly economy.

Dawit Wolde Giorgis, head of the Ethiopian government's Relief and Rehabilitation Commission, called for "the orderly and voluntary repatriation of our compatriots so that they could, in dignity, be provided with relief assistance within their own country."

Today's visit also follows an Ethiopian warning to Sudan last week. The Ethiopian Foreign Ministry, in a statement it said was issued in response to a story in The Washington Post, said it "will closely monitor the response of the Sudanese government" to U. S. plans to ship 100,000 tons of relief food into northern Ethiopia via Sudan.

The statement added that Ethiopia considers the U.S. plan to distribute food in the rebel-held north to be a "clear demonstration of the arrogance of the United States administration to trample under foot the basic rights of peoples."

Since the pro-American government of Jaafar Nimeri was toppled April 6, there has been speculation among diplomats here that Sudan and Ethiopia could go a long way toward winning their respective civil wars by agreeing to stop helping each other's rebels.

There have been, however, no official statements by the government here to indicate that it has backed off from its support of the Sudanese rebels.