WASHINGTON — Amid upbeat expressions from both sides, Secretary of State George P. Shultz and Soviet Foreign Minister Eduard A. Shevardnadze agreed Wednesday that "some progress" has been made in arms control talks.
As their planned three-day negotiation passed its midpoint, the issue of limiting nuclear tests was separated from the main arms discussions for detailed negotiations by experts. The move stirred hopes that the United States and Soviet Union would move soon toward full-scale negotiations aimed at reducing the number and power of underground weapon blasts.
More significant arms issues, involving reductions in arsenals, also appeared to move forward, though without any tangible major developments.
Some Soviet statements in the talks hinted at new ways of addressing deep cuts in strategic offensive weapons, sources said, and the few remaining obstacles to an agreement eliminating medium-range missiles were intensely argued. A treaty on medium-range missiles, believed virtually completed, would probably be signed at a U.S.-Soviet summit meeting later this year.
The possibility of banning chemical weapons also may be more likely, though this was caused mainly by significant Soviet concessions during the last year in Geneva rather than to new initiatives by Moscow this week.
Working groups of specialists met through Tuesday evening and Wednesday on arms control, on bilateral diplomatic U.S.-Soviet matters such as the U.S. Embassy construction in Moscow and on regional issues such as conflicts in Afghanistan and the Mideast.
At one point, Shevardnadze was asked by reporters what he thought of optimistic U.S. statements of the day before.
"We also made some optimistic statements," he replied.
He was also asked if the working group on arms control had made progress. His reply suggested a garble in translation: "If we didn't expect any, then we wouldn't be here," he said.
Shultz interjected: "They made some progress. The minister (Shevardnadze) and I agreed that, while they were not perfect, they were the best we had."
The optimism was pronounced during luncheon toasts at the Soviet Embassy, which State Department spokesman Charles Redman described as "very positive and forward looking." He said that Shultz spoke of the problems and progress that had characterized Soviet-American relations over the years, adding: "In the past, there has been more emphasis on problems, but now the emphasis is on progress."
Shevardnadze told reporters at the end of Wednesday's talks that, while progress had been made on the intermediate-range missile issue, "there are some elements we have to sit and work (on) some more. (But) we have given categoric instructions (to working group officials) to seek solutions.
"Tomorrow, we will talk (with the press) in a more specific way," Shevardnadze promised. He and Shultz have scheduled press conferences for this afternoon.
Talks about nuclear testing have been at an impasse for years because the Soviets want the negotiations to be aimed at ending all nuclear tests, while the Reagan Administration believes that some testing will always be required to ensure the reliability of nuclear weapons that are kept as a deterrence.
The Administration, as a first step, wants better methods for policing agreements on nuclear testing underground that were signed more than a decade ago but never ratified. Those agreements set an upper limit of 150 kilotons, the equivalent of 150,000 tons of TNT, on the blasts. Tests in the air, sea and space are banned.
With better verification techniques, the Administration would submit the treaties for congressional approval. Then it would begin talks aimed at setting a lower limit on the power of tests and an annual quota of tests, in conjunction with reductions in nuclear weapons themselves. Testing would end only when nuclear weapons are eliminated.
The Soviets, after adamantly opposing this approach, have softened their position. The differences between the two sides now center on two issues: joint experiments at the test sites of both nations on verification and common language to describe new negotiations that papers over their different goals.
The Soviets last month signaled their willingness to conduct joint testing experiments, an idea originally proposed by President Reagan at his meeting with Soviet leader Mikhail S. Gorbachev in Reykjavik, Iceland, last year. These would consist of detonating explosions of known power at test ranges to determine the most accurate system for measuring the force of the blasts.
Currently, the U.S. and Soviet techniques for measuring the blasts are quite different in principle and may give different results.
The two sides have agreed that such experiments will be part of the mandate given to their negotiators when full-scale talks on nuclear testing are authorized. If Shultz and Shevardnadze agree on the mandate, the talks can be announced either soon or at the prospective summit between Reagan and Gorbachev later this year.