The U.S. naval buildup in the Persian Gulf area has been driven by political rather than military concerns, Navy Secretary James H. Webb Jr. said yesterday, adding that he does not know when the United States will be able to reduce force levels there.

Returning from a three-day trip to the region, Webb said U.S. naval forces will remain at high levels in the region until "we receive the appropriate political signals from the Iranians."

"We don't want to continue to operate at this level," he said, adding, however, that the Navy is making "long-term plans" for its presence in the region.

Webb said U.S. protection of reflagged Kuwaiti ships in the gulf area has raised concern that "we would be pulled into an obligation that did not have specific goals attached to it so that we couldn't measure when the goals had been met."

It has been widely reported that Webb opposed a substantial part of the gulf buildup. Yesterday, he sought to play down disagreements with Defense Secretary Caspar W. Weinberger and other top department officials, saying, "Advice is not dissent, and expressions of concern are not opposition."

Webb said, however, that he is uncertain how U.S. officials will determine when international shipping lanes are safe enough to allow reduction of forces in the region.

"There are many aspects of the political environment that have to be resolved, and that's above my pay grade," Webb said.

He said the harsh weather and strenuous schedules of the escorting missions are exacting a heavy toll on personnel and equipment.

"When you have to move ships out that should be in port or undergoing other training, you begin to wear out your people," he said.

One Navy official familiar with the operations said yesterday that the Navy had been airlifting supplies to the region twice a month before the escorting missions. Now, he said, supplies are being flown there twice daily.

In addition, the official said, helicopter parts that normally can be used for a month must be replaced every other day because of the pace of operations and the weather.

Webb said he met with government officials in Bahrain and went aboard seven U.S. ships during his three-day visit. He said he found the ship's officers and crews "highly motivated."

In a related political matter, Webb denied that Adm. James A. (Ace) Lyons Jr., commander of the U.S. Pacific Fleet, had been forced to resign because he criticized Pentagon handling of gulf operations.

Webb lashed out at his predecessor, John F. Lehman Jr., who told The Washington Post that he considered the move to oust Lyons "the revenge of the nerds."

Webb said, "It's no secret that my predecessor played a great deal of favoritism in the promotional and assignment aspects of officers in the naval service. Ace Lyons was one of his favorites, and one would expect that sort of comment."