U.S. arms control negotiator Paul C. Warnke said yesterday that a "shell game" mobile missile system under consideration at the Pentagon is consistent with a new strategic arm pact became provision can be made for the Soviet Union to count the U.S. missile launchers.

The question of verification is among the most controversial aspects of the proposed system, which is designed to frustrate Soviet target planners by shifting hundreds of land-based U.S. missiles secretly among thousands of possible launching sites.

"Conceptually I don't have any problem with it," Warnke said in an interview about the "shell game" idea. He pointed out that in existing and planned strategic arms agreements, limitations are placed on "strategic missiles launchers" rather than on silos or launching points. Each of the superpowers is entitled to verify what the other side has and how many - "but not where they are," Warnke said.

Warnke did not spell out the method which would be worked out for the Soviets to verify the number and character of U.S. mobile missile launchers, while still maintaining secrecy about their whereabouts. But he suggested that counting the launchers on the production line is a likely possibility.

Some arms control experts have expressed fear that a nuclear "shell game" could undermine the concept of limits on strategic armaments by introducing secrecy and deception for powerful landbased weapons instead of certainty and mutual confidence. Any system which is permitted for the United States under a strategic arms limitation talks (SALT) agreement would also be permitted for use by the Soviet Union, and these experts doubt that the United States would be satisfied with a Soviet land-based missile system which moved in secrecy and thus could not be kept in view by spy satellites.

Warnke said that ideas for mobile land-based missiles which include the use of decoys and dummies would not be permissible under SALT. The rule is that "if it looks like a launcher, it counts as a launcher," he said.

Artists' conceptions of the proposed MX missile, as released by the Pentagon, show a massive canister pulled by a very heavy tractor. One plan for launching the missile, which would be 71 feet long and weigh 190,000 pounds, is to "pop up" the canister in a previously prepared silo.

An arms control impact statement submitted to Congress last March by the Carter administration said the "verification uncertainties" in connection with a mobile intercontinental ballistic missile such as the MX "could raise new problems in United States-Soviet relations" and that if major uncertainties were allowed, "they could undermine public confidence in any new agreements that are reached."

The statement said mobile ICBMs would be difficult but not necessarily impossible to count, "particularly if verification aids or cooperative measures were included in arms control agreements." It went on to say that such measure would be "a significant change" from the accepted methods of verifying previous SALT agreements and that "the negotiability of such measures remains to be seen."

Warnke repeated the U.S. position, most recently by Defense Secretary Harold Brown in a speech Tuesday, that a "shell game" system is permitted under the agreed draft text of the proposed SALT-II pact. Warnke confirmed that Soviet negotiators have expressed concern about the "shell game" but said they were reacting to press accounts which may not depict the final U.S. system, if any, that is chosen.