Although the United States claims to have achieved its major goals at the recent World Administrative Radio Conference (WARC) in Geneva, top FCC officials said yesterday that the toughest battles in the international telecommunications arena are yet to come.

FCC foreign affairs chief Kalmann Schaefer said there are 21 major international radio conferences scheduled over the next six years.

One of the conferences, a 1984 meeting to plan for outer space services, "will impact seriously on the communications services that will be offered in the late 1980s" Schaefer said.

He said that and other conferences could, for example, impose severe limitations on the use of commerical satellites.

He said two other conferences were also considered by the FCC to be extremely important: a 1983 meeting of Western Hemisphere countries to structure regional broadcast satellite usage, and a 1982 conference to plan the future structure of the International Telecommunications Union, the United Nations affiliate that regulates use of international airwaves.

Schaefer summarized the results of the 1979 WARC, which ended last month:

"There were a few unfortunate political skirmishes," he said, "but the effectiveness of the ITU was not compromised."

There had been fears before the conference that developing countries were planning to interject politics into the traditional technical meetings, and call for a "new world information order" that would, for example, require that certain frequencies remain unused until Third World countries could use them.

The U.S. and other industrialized nations were sharply opposed to such planning, arguing that such a system would waste valuable frequencies.

Instead, they argued, the radio bands should be allocated on a first-come-first-serve basis, with the understanding that in the future, new entries would have to be accommodated somehow.