The United States will seek vigorous action by the U.N. Human Rights Commission on cases ranging from Andrei Sakharov's banishment and the Soviet invasion of Afghanistan to the taking of hostages in Iran, according to the chief U.S. delegate to the commission's six-week meeting that opens Monday in Geneva.

Also to be debated are Cambodia's treatment of refugees and the "disappearances" of dissidents, a spreading phenomenon that has become particularly notorious in Argentina.

Philadelphia lawyer and human rights expert Jerome Shestack is leading a 10-member delegation that he called "the best prepared ever" to what promises to be the liveliest annual meeting yet of the 34-year-old commission.

The U.S. government, after decades of frustration with the slow-moving commission, has shown a revived interest in its potential as a focus for international indignation.

Shestack said in a telephone interview that this year the United States has the issues that will elicit widespread support from the commission's newly expanded 43-nation membership.

On the Sakharov case, Shestack said, "The mean-spirited and malicious" Soviet silencing of the dissident last month "is part of a larger problem of people who want to speak out on human rights in their countries."

The Sakharov issue as well as "the impediments to refugee relief" in Cambodia are examples of cases "on which we will cooperate closely with like-minded countries," he said.

Assistant Secretary of State Charles W. Maynes underlined the renewed U.S. interest in the commission saying that "while it has moved far too slowly, in the last three years it has done things never done before."

"We hope to build on the new trend," said Maynes, adding that public action by the commission "can be worth a considerable amount . . . a lot of countries care."

Shestack described the issue of disappearances as "a prime example of repression" that he hopes to see dealt with in Geneva.