Soviet-American relations have cooled somewhat in recent weeks an almost natural consequence of deep-seated differences between the superpowers over the Middle East and Africa.

Several informed Western sources here say the "slight downturn," as they termed it, is not regarded as serious, but simply reflects the conflicting views and interests of the two global powers in these volatile areas.

In recent days, the Carter administration has accused the Soviets of a massive airlift of weapons to its new ally, Ethiopia, and has maneuvered between Cairo and Tel Aviv to keep Egyptian President Anwar Sadat's peace initiative afloat.

The Soviets have responded angrily to both moves, denying the former and attacking the latter as an obvious attempt by the Americans to force a separate peace between Israel and Egypt, leaving the other Arab nations out in the cold.

"They have taken their shots from Washington in recent days, so you have to expect this," said one seasoned diplomat. "The Americans have accused the Russians as well of a proxy war in Indochina, and they are boound to look at all these things in a very poor light."

Although the Soviets have admitted sending "material and technical aid" to Ethiopia, a description used to described the supply of arms and experts, it has denied mounting a massive airlift or any direct participation by Soviet military or technical advisers in the two-front war being fought by the Marxist Ethiopian government against Tritrean guerrillas in the north and Somali-backed insurgents to the east.

At the same time, the Soviets have suggested that it is the Americans, through unnamed third countries, who have been supplying arms to the Somalis, until last fall the chief clients of the Kremlin in the strategic Horn of Africa.

The Kremlin has gone to unusual lengths in its denial, last week issuing a strong denunciation of the U.S. allegations through Tass, the official government news agency.

With regard to the Middle East, the Kremlin quoted, with undisguised satisfaction, unnamed Middle East observers as noting that Sadat in a speech to his parliament "lacked any proposals regarding some way out of the present impasse. Observers conclude that Sadat intends to go on relying on the mediatory services of the U.S. in his deals with Israel . . ."