The Bush administration said yesterday that the United States would use force to stop any ships, including those carrying food, that attempt to break an international trade embargo placed on Iraqi commerce last week.

Secretary of State James A. Baker III said the administration yesterday received a letter from the Kuwaiti government that "requested of us and of other nations support for enforcement of the U.N. economic sanctions." Baker said the "interdiction" policy "would begin almost instantly."

Baker's statement came as Pentagon officials said the buildup of U.S. forces in Saudi Arabia was ahead of schedule. The forces are being joined by troops from a number of Arab nations, including Egypt, to protect Saudi Arabia from Iraq.

The Pentagon also announced that an Air Force maintenance technician was killed in a runway accident in Saudi Arabia, the first American death since U.S. forces began to arrive.

The administration has hinted for two days that it would move to block any Iraqi efforts to evade the economic sanctions ordered by the U.N. Security Council last week because of Iraq's invasion of Kuwait. President Bush on Friday issued a warning that he was prepared to "do whatever is necessary to see that exports from {Iraq} . . . do not go forward." And on Saturday Bush said he believed he had legal authority to stop Iraqi ships if they attempt to break the U.N. embargo.

The president -- during a round of golf at Kennebunkport -- was asked whether the United States planned to block food shipments to Iraq. He replied, "Everything. Everything."

Baker, on ABC News's "This Week With David Brinkley," when asked whether the United States intended to stop aircraft as well as ships, said only, "We're going to take measures that are necessary and proportionate."

The administration is avoiding the words "blockade" and "quarantine" because, under international law, those terms can be interpreted as acts of war. Baker said he would call the effort "interdiction."

But Bush, asked whether he would call the naval operation a blockade, said he considered it "to be in accord with . . . action taken by the United Nations."There is "no point getting into all the semantics. The main thing is to stop the oil from coming out of there. That's what we're doing . . . ," he said.

A senior administration official, speaking yesterday on the condition that he not be identified, said, "We will fire on a ship if it won't stop. . . We'll do the usual things -- warn them off, fire a shot across the bow. But if it comes to that, there is no question what we will do."

Baker said Kuwait had "made the formal request now that is needed under Article 51 of the United Nations Charter for the United States and other countries to have a legal basis for stopping the export of oil and that sort of thing . . . . We now have the ability, the legal basis, for interdicting those kinds of shipments."

The U.N. Security Council last week ordered far-reaching economic sanctions against Iraq for its invasion of Kuwait. While the sanctions are theoretically binding on all 159 member nations, no enforcement provisions were voted on. However, Article 51 of the U.N. Charter authorizes countries under attack to act in self-defense and seek help from other nations.

The administration hopes Egypt will "close the Suez Canal to all ships bound for Iraq or whose cargoes are bound for Iraq via the Jordanian port of Aqaba," one official said. "Closing the canal is like slitting a major vein," he said, because the canal is critical to Iraqi commerce with Europe.

Another senior official emphasized, however, that the administration has been talking about the sanctions with many of Iraq's trading partners and no specific request has been made to Egypt to shut the canal to Iraqi shipments.

U.S. forces continued their buildup in the Mideast yesterday as senior Defense Department officials declined to place any limits on the number of troops likely to be sent.

Undersecretary of Defense Paul D. Wolfowitz said in an interview on Cable News Network, "We will put in whatever level of troops we need, and we're bringing in more and . . . more every day."

"We are not being specific about figures," he said, "we're just putting in everything that we can get there as fast as we can get it there. When we feel that we have enough, then we will stop."

Wolfowitz said the total was "going to depend partly on what he {Iraqi leader Saddam Hussein} does and how he reacts. It's going to depend partly on how many Egyptian forces and other forces come in." Last week, Pentagon officials said the U.S. buildup could continue until 200,000 troops are deployed.

Bush, talking with reporters at his vacation retreat, said he telephoned Syrian President Hafez Assad to thank him for his willingness to send Syrian troops as part of an Arab League effort to protect gulf states from Iraq. Apparently, however, no Syrian troops have yet arrived in Saudi Arabia.

Bush said the two had "a good talk," and said he told Assad that "I am very pleased we're looking at this in the same way" and that Assad said he "was pleased to be together on this." U.S. relations with Syria, listed by the State Department as a country that supports terrorism, have been strained for years.

Later, Bush said he would also welcome a reported offer of help from Iran, another nation with which the United States has long had tense relations. "Anybody to help enforce these sanctions, that's who we want," he said.

Meanwhile, the commander of the U.S. military effort in the Mideast told reporters yesterday that the deployment of is running ahead of schedule and Iraq "would pay a price" if it attacked Saudi Arabia.

Gen. H. Norman Schwarzkopf, commander of the U.S. Central Command, said the Iraqis continued to move reinforcements into Kuwait. Those forces are taking up defensive positions, he said, and some were "right down literally on" the Kuwait-Saudi Arabia border.

"There's no question about the fact that they have dug in right now for a strong defense," he said, briefing a media pool at MacDill Air Force Base in Florida. But Schwarzkopf noted that Iraqi troops took a similar defensive stance before invading Kuwait 10 days ago. "They have the capability to do just about anything they want to," he said.

Defense Secretary Richard B. Cheney, interviewed on NBC News's "Meet the Press," said Saddam "has upwards now of 200,000 men in Kuwait or southern Iraq" and had "close to 6,000 tanks {and} . . . a large air force. And if we're going to carry through on our commitments in that part of the world, we have to deploy significant military force."

Pentagon officials said they were sending a battle group headed by the carrier USS John F. Kennedy to relieve one of the three battle groups in the gulf region. The U.S. naval forces are intended to provide support for troops on the ground in Saudi Arabia as well as enforce the embargo against Iraq.

The Pentagon identified the airman killed in Saudi Arabia as Air Force Staff Sgt. John Campisi, 30, an aircraft maintenance technician from Covina, Calif., who was assigned to Offutt Air Force Base in Nebraska. Pentagon officials said a preliminary investigation indicated Campisi was hit by a truck on a dark runway.Staff writers Dan Balz in Kennebunkport and Molly Moore and David Hoffman in Washington contributed to this report.