The Carter administration, stung by former secretary of state Henry A. Kissinger's charge that U.S. policy favors the radical guerrillas in Zimbabwe-Rhodesia, said yesterday it is "not tilting" toward any side and seeks only to "promote a democratic solution" to the civil war there.

The administration defended its policy in a lengthy statement issued by the State Separtment in response to a Kissinger interview published yesterday by The Washington Post.

In the interview, Kissinger criticized President Carter's finding last month that the recent elections leading to a black majority government under Prime Minister Abel Muzorewa were not sufficiently free and fair to warrant ending U.S. economic sanctions.

Kissinger said the administration, in justifying continued sanctions by questioning the Zimbabwe-Rhodesia constitution, had put the United States on the side of "ideological radical" guerrillas who refused to take part in the elections and who continue to seek power through armed conflict.

Although it refused to say it was responding directly to Kissinger, the State Department quickly rushed out a restatement of "the key elements of the administration's Rhodesia policy."

That statement, read by spokeman Tom Reston at a press briefing, said "From the outset, the administration as sought to promote a democratic solution in Rhodesia. It was for that reason that free elections have been the centerpiece of out initiative."

The statement then took issue with Kissinger's contention that the radical rorces want a system of majority rule "so extreme as to be incompatible with the survival of the [white] minority . . ."

"A key aspect of our settlement efforts," the statement asserted, "has been our insistence with the British on the protection of minority rights, and on the right of the white minority to a role in a future Zimbabwe. We do not define majority rule in ways which would leave minority rights unprotected."

The statement also argued that the administration, in pursuing a solution that would embrace all the contesting factions including the guerrillas, was not on a course "kissinger characterized as favoring "the radicals against the moderates."

"We have made clear . . . that no party should be allowed a veto over a fair political process," the statement said. "And no party has a veto over our policy. We would give our full support to a fair process, even if some parties refused to cooperate."

Lastly, the statement said Carter and Secretary of State Cyrus R. Vance have noted "that encouraging process has been made in Zimbabwe Zimbabwe-Rhodesia" and have expressed interest in a dialogue with Muzorewa.

Muzorewa is scheduled to visit here unofficially next week and is expected to meet with Vance. There also have been hints that Carter will yield to the urging of Muzorewa's congressional supporters and invite him for a White House talk, but Reston said yesterday he had "no information on that."

"In short," the statement concluded, "we are not tilting towards one side or the other. The most effective way to advance our interests and prevent increasing outside millitary involvement is to work for a peaceful settlement and a fair political process open to all parties."