The Soviet Union has suspended its airlift of arms to Ethiopia, but it is too early to know whether the suspension represents a change of policy, administration officials said yesterday.

The Soviets, over the protests of the United States, have been shipping tons of planes, tanks and small earms to Ethiopia to help that nation fight successionist and Somalian-backed forces.

But, administration officials said yesterday, no Soviet cargo planes have been spotted flying into Aden, the capital of Southern Yemen which has served as a terminal for the shipments, or Addis Ababa, Ethiopia's capital, since late December.

One official speculated yesterday that Pakistan may have protested Soviet overflights and warned against any new ones.

Other U.S. officials speculated that Moscow has decided to hold back on any further air shipments until Ethiopia has had time to absorb all the weapons it already has received.

Administration officials doubted that the lull in the airlift represents a major shift in Soviet policy, as much as they would welcome this.

The U.S. position was stated by State Department spokesman Ken Brown on Dec. 13: "The superpowers should stay out and leave it to the Africans to find a solution . . ."

Not only has the Soviet Union shipped to Ethiopia such weapons as the Mig-21 fighter, T-54 tank and the battlefield rockets known as the "Stalin Organ" they have stationed advisers and logisticians there administration officials have complained.

The United States estimates that there are between 500 and 1,500 Russians in Ethiopia, in addiiton to about 1,000 Cuban military advisers.

Defense officials fear that Soviet arms shipments represent a decision by Moscow to make Ethiopia its biggest and most influential beachead in Africa.

From Ethiopia, the Soviets would be in easy striking distance of oil-rich Saudi Arabia across the Red Sea. Ethiopia could also replace the naval facilities the Soviets lost when they were asked to leave by Somelia.

Egypt's president, Anwar Sadat, has expressed concern about the military threat from Ethiopia, a concern which would deepen if Soviet arms continue to go into Ethiopia.

Although one defense official yesterday described President Carter's arms policy toward Africa as one of "interested neglect," the administration does plan to send a squadron of F-5 fighters to Sudan, the country between Ethiopia and Egypt, if Sudan can get the money to pay for them.

However, the Pentagon view is that it will be years before Sudan can field anyvsignificant kind of modern military force.

In contrast the arms already in Ethiopia are expected to escalate the war there in the immediate future unless peace negotiations succeed. Most of the Soviet arms are believed to be headed to beleagued Ethiopian forces in the Ogaden Desert where Somali-backed troops are reported to have captured most of the region.

U.S. officials have been expecting an Ethiopian counteroffensive there for weeks, but it has not materialized.

Yesterday, the State Department posted a notice stating that Maj. Dawit Wolde-Ghiorgis, permanent secretary of the Ethiopian ministry of foreign affairs, had conducted a "wide ranging discussion" with Richard M. Moose Jr., assistant secretary of state for African affairs, on Wednesday.

But State officials said last night that the meeting had no bearing on the suspension of the Soviet airlift to Ethiopia.