The representative of the United States who will monitor Zimbabwe-Rhodesia's progress toward majority rule will not have diplomatic status and will be "nothing as formal" as a presidential envoy, according to Zbigniew Brzezinski, the president's national security affairs adviser.

But the unnamed representative of unspecified rank will have the task of reporting back to the administration whether the prime minister, Bishop Abel Muzorewa, has made enough progress to broaden his support and persuade President Carter to lift economic sanctions against the country.

Britain's new conservative government sent its own high-level emissary to Salisbury last month for the purpose of establishing contact with the Muzorewa government and paving the way for eventual recognition. By stating unequivocably that the U.S. representative will not be as high on the diplomatic ladder as a presidential envoy, Brzezinski removed any doubt that the U.S. representative's purpose will be to monitor Muzorewa, not to be the forerunner to an ambassador.

"We're talking about someone who would be in a position to be on the spot and report to the U.S. government the actual circumstances and the changes that we hope will be taking place," Brzezinski said. He added later, "I'm sure we can find the individual and the proper circumstances for him."

Brzezinski declined to specify what steps Muzorewa must take to meet the administration's requrements for lifting sanctions, but he did not rule out the possibility of new elections.

"We have confidence that Bishop Muzorewa himself recognizes the need for further change," Brzezinski said.