BRUSSELS, DEC. 1 -- The Kuwaiti government has approved a U.S. request to station a floating base in Kuwait's territorial waters in the northern Persian Gulf, Pentagon officials said here today.

The decision to base U.S. military operations on a barge inside Kuwaiti waters comes amid concerns by some Pentagon officials, including Defense Secretary Frank C. Carlucci, that it could be vulnerable to Iranian attacks.

Other officials also have raised concerns that locating the barge in Kuwaiti waters could force the United States to provide defense for Kuwait in future attacks.

The brief written statement about the barge was the Pentagon's first official acknowledgement that the U.S. military is using fortified barges as bases in the gulf.

The U.S. military command in the gulf has made highly effective use of two barges at other locations in the waterway as floating fortresses aimed at countering Iranian mine threats and speedboat attacks against U.S.-protected ships.

Iran has launched three Silkworm missile attacks against ships and facilities in the Kuwaiti harbor in recent months. In each instance, the U.S. government said it was not obliged to provide protection for Kuwait inside its territorial waters.

The Kuwaiti-owned barge would be the third such mobile base the United States has positioned in the gulf to support its escorts of American-flagged Kuwaiti tankers.

The other two barges are kept in international waters.The Navy has equipped the barges with attack helicopters, fast patrol boats, Army and Navy commando teams, and intelligence gathering units.

U.S. military officials are "working out the details" of the new barge base, according to the Pentagon statement released here where Carlucci is attending a meeting of North Atlantic Treaty Organization (NATO) defense ministers.

The agreement with the Kuwaiti government comes after vocal criticism from some congressional and military officials early in the reflagging operation that Kuwait was not providing enough support for the escorting missions.

The United States has increased dramatically its military presence in the Persian Gulf with minesweeping vessels, special operations forces and additional warships and aircraft since it began escorting the reflagged tankers in July.

U.S. defense officials have said in recent weeks that Kuwait, Saudi Arabia and other Persian Gulf nations fearful of retaliation from the Iranians have quietly provided some basing support for U.S. military operations.

Today's statement came in response to a Washington Post story Sunday which reported that the United States had rejected Kuwait's offer to position a barge inside its waters.

When asked about the report Sunday night, Carlucci told reporters traveling with him, "That's the first I've heard about it. . . . It must have been made at a lower command level." Carlucci, who was sworn in as defense secretary barely a week ago, added, "I'm not sure we need one up there {in Kuwaiti waters}. It's vulnerable . . . ."

A western official in the region said that Kuwait approved the barge operation in Kuwaiti waters in principle about six weeks ago. He said that there undoubtedly was some confusion because Kuwaiti officials had not received a U.S. response during that period and assumed the offer had been rejected, Washington Post correspondent Patrick E. Tyler reported.