Defense Secretary Caspar W. Weinberger said yesterday that Western military power in the Persian Gulf would continue to grow, indicating that the United States and several other nations were planning to send additional warships and sailors to the troubled region.

Without naming specific countries, Weinberger suggested that other European powers -- in addition to Britain and France, which already have dispatched six modern mine sweepers and an aircraft carrier to the region -- will soon be sending military vessels to the gulf.

"What we have now is sufficient to do what is required today, but that is by no means static or final," Weinberger said in an interview with the Los Angeles Times. "The important thing is to have increased capabilities . . . in that area."

Dutch officials have nearly decided to send mine sweepers to the region, Pentagon sources said, and Italy is debating whether to contribute. Weinberger hinted that other European nations might be considering joining the force and that Japan might help finance the operation.

Japan, which gets almost two-thirds of its oil from gulf states, is prohibited by its constitution from operating a seagoing navy.

The United States has 40 Navy ships and 25,000 sailors in and around the gulf, according to the Pentagon and independent estimates. Included are an aircraft carrier, a battleship, a helicopter carrier and several amphibious assault ships carrying about 1,800 Marines.

The Navy is preparing to send five high-speed hydrofoil missile patrol boats from their port at Key West, Fla., to the gulf, sources said. The vessels could be used to intercept machine-gun-equipped Iranian speedboats that have been shadowing U.S. warships and commercial vessels in the gulf. Iran is suspected of using the speedboats to lay mines in the gulf and could be preparing to use them in suicide attacks.