The Goodwill Games in Moscow this summer pose a potential threat to the Olympic movement, a top U.S. Olympic Committee official said yesterday in Seoul.

"The USOC is not involved in the Goodwill Games as an NOC," USOC Secretary General George Miller said in a statement read at the General Assembly of the Association of National Olympic Committees. "But we would take no position that would jeopardize the Olympic movement.

"As an NOC, we view these games as a commercial venture . . . and we urge all NOCs to review their participation in the future."

Miller said he knew of no national Olympic committee directly involved in the July 5-20 Goodwill Games, but said that such involvement could occur. The second Goodwill Games are set for an as-yet-undetermined site in the United States in 1990.

The Goodwill Games are the product of an unusual alliance between Atlanta broadcasting millionaire Ted Turner and the Soviet Sports Ministry . . .

In other action in Seoul, the International Olympic Committee expanded its rules on drug use, including a lower limit on caffeine and a total ban on diuretics.

IOC spokeswoman Michele Verdier told reporters the practical effect of the new caffeine limit of 12 micrograms per milliliter would rule out the consumption of more than 6 to 7 cups of coffee a day.