Soviets Formally Present New Plan to Ban Missiles in Europe : U.S. Says It May Have ‘Fine Print’ Needed for Accord

American and Soviet arms control negotiators met in special session in Geneva today and the Soviets presented Mikhail S. Gorbachev’s new proposal to eliminate medium-range missiles in Europe.

In Washington, the White House welcomed the Soviet proposal as “a positive development” that could contain the kind of “fine print” needed to work out an arms agreement.

The new Soviet offer was submitted at a one-hour meeting at the Soviet mission in Geneva. The session was attended by the top three negotiators from each side and their aides, headed by Deputy Foreign Minister Yuli Vorontsov of the Soviet Union and Max M. Kampelman of the United States.

The atmosphere was friendly going into today’s meeting, with Kampelman and Vorontsov smiling at each other, shaking hands and exchanging pleasantries.

Negotiations Extended

U.S. spokesman Terry Shroeder said after the meeting that the two sides had agreed to extend their negotiations on medium-range nuclear forces beyond the scheduled closing date of Wednesday.

Shroeder said the length of the extension will be decided by the chief negotiators on medium-range weapons, Lem Masterkov and Maynard Glitman.

The other two negotiating groups, on long-range nuclear weapons and space and defense systems, were to end on schedule Wednesday, Shroeder said.

White House spokesman Marlin Fitzwater said today that the proposal offered in Geneva, which separates the issue of medium-range missiles from the deadlock over the U.S. “Star Wars” missile-defense program, was “an apparent Soviet agreement to move forward” in the so-called Euromissile talks.

Careful Analysis Required

However, a senior Administration official said a careful analysis would be required before U.S. officials determine how far the offer may go toward resolving differences over verification and the treatment of short-range missiles.

While the Soviet proposal may provide reason for optimism, the official said, “I think we’re talking about months, at a minimum” before an agreement could be reached.

At the same time, the official refused to take a view expressed by some arms control experts that the Soviet movement on medium-range missiles reflects the hopelessness of reaching an agreement on strategic and space arms because of the impasse over Reagan’s “Star Wars” program.

The Soviet proposal would limit the United States and Soviet Union to 100 warheads apiece on medium-range missiles. Those weapons, now targeted on Europe and--in the case of the Soviet Union--on portions of Asia, would be confined under the agreement to Asia and the U.S. mainland.

Those limitations mirror ones discussed at the Iceland summit last October. The major difference is that the Soviets no longer make that agreement conditional on progress in other areas, such as curbs on the development of anti-missile systems.