President Francois Mitterrand today called on both superpowers to drop some of their demands at the Geneva talks on intermediate-range nuclear weapons in Europe.

In a televised interview, the French president said that the Geneva negotiations would not succeed on the basis of the rigid positions adopted by the Soviet Union and the United States. He criticized both Soviet proposals put forward at the talks and the zero option originally developed by the Reagan administration, which called on Moscow to dismantle all its SS20s.

Mitterrand's comments on intermediate-range weapons came as President Reagan was unveiling details of a more flexible U.S. negotiating stand for the parallel talks on intercontinental strategic weaponry, also in Geneva.

The French leader indicated that he would support a compromise along the lines of the proposal worked out by the two principal U.S. and Soviet negotiators during "the walk in the woods" last year. He said the negotiations "could have succeeded" on the basis of these proposals, which were not accepted by either side.

Mitterrand, who joined other western leaders in signing a joint declaration at Williamsburg supporting the deployment by NATO of U.S. intermediate-range missiles in Europe in the event of failure at Geneva, said the present talks on such weapons were getting nowhere.

Mitterrand made clear that he considered that at present the Soviet Union enjoyed a monopoly of intermediate-range weapons in Europe and it was necessary for the United States to correct this imbalance.

His attempts to make his remarks appear even-handed seemed designed to appease his Communist coalition allies, who have complained about his decision to sign the Williamsburg declaration on security. His basic position, however, remains that he is in favor of the deployment of U.S. missiles late this year if the Geneva negotiations do not succeed.