The White House said today its naval barricade of Iraqi ships is taking hold as the United States and its allies squeeze Saddam Hussein economically so the Iraqis cannot ``maintain their war machine.'' The Bush administration said bluntly today that even food would be withheld from Iraq. ``You don't give them the essentials that enable them to carry on the war,'' White House spokesman Marlin Fitzwater said. In Saudi Arabia, where American troops are building a massive defense against any further Iraqi aggression, the acting chief of staff for U.S. troop operations told reporters, ``I think our position grows stronger with each day that goes by.'' As Maj. Gen. Don L. Kaufman spoke, the steady drone of planes brought more soldiers and hardware to the Saudi desert. Kaufman said planes were landing virtually every 10 minutes or so with their military cargo. On the economic front, Fitzwater said the sanctions endorsed by the United Nations are hurting Baghdad. ``The purpose of the embargo is to put the pinch of them,'' Fitzwater said in Kennebunkport, where President Bush is vacationing. ``We assess the impact of the embargo as excellent.'' He said the White House had ``obvious humanitarian concerns'' about prohibiting food imports into Iraq. But he added: ``The purpose of the sanctions and the embargo is to put the pinch on them. It seems fairly obvious to me you don't let foodstuffs and other things go in that are subject to the sanctions. The purpose is not to let supplies go in that allow them to maintain the war machine, allow them to maintain their aggressive takeover of Kuwait.'' Asked about reports that Jordan was allowing Iraqi shipments through, Fitzwater said, ``We are hopeful that Jordan will comply. They have said they will abide by the sanctions.'' Fitzwater also said the White House reported ``two or three ships in recent hours that have turned away or been turned away or at least have otherwise not landed with their cargo.'' An Iraqi tanker tried to dock at a Saudi terminal to take on oil, but was turned away by Saudi officials, diplomatic sources in the region reported. Bush and his top aides are avoiding the word ``blockade'' to describe a U.S. decision to use whatever means necessary to choke off Iraq's oil trade and imports of other goods, including food. But their intention was clear. ``I consider interdiction of shipping to be in accord'' with United Nations economic sanctions, Bush told reporters Sunday. ``No point getting into all these semantics. The main thing is to stop the oil from coming out of there and that is what we're going to do.'' Diplomatic sources at the oil terminal near Yanbu, Saudi Arabia, said the Iraqi tanker al-Qadissiyah, which could carry up to 900,000 barrels of oil, failed in its attempt to moor Sunday night because three tug boats that normally would help have been taken out of the water. The sources, speaking on condition of anonymity, said the tanker sailed away today, after its apparent attempt to defy a U.S. declaration that its warships would enforce a U.N. embargo aimed at forcing Iraq's Saddam Hussein to give up his forced annexation of Kuwait. Prince Bandar Bin Sultan, the Saudi ambassador to Washington, said on ``Good Morning America'' that Saddam should not try to make the Israeli territories a part of the Kuwait crisis. ``He is mixing the issues,'' the ambassador said. ``That is not an excuse for an Arab country to go an invade another Arab country.'' The United States intensified its military fortification of Saudi Arabia and the surrounding seas over the weekend, sending in Marine and Army air assault troops and shipping Patriot surface-to-air missiles and other sophisticated air-deployed weapons to the region. Sources who disclosed the movements said Pentagon planners assumed that, in the event of an Iraqi attack, an initial air battle could be decisive. The commander of the U.S. military action, Gen. H. Norman Schwarzkopf, briefed reporters at MacDill Air Force Base in Florida on the logistical difficulties of transporting troops and backup equipment 7,000 miles by air and 12,000 miles by sea. Schwarzkopf said the Iraqis are ``dug in right now for a strong defense.'' ``We have built up a great deal of force over there now ... and if they do make an attack they are going to pay a price for it,'' he said. Schwarzkopf said troops would be on guard against terrorists as well as Iraqi guns and gas. An estimated 50,000 troops are committed to Saudi Arabia in the initial deployment, with contingency plans for a force up to 250,000. ``I would never tell you that the American forces that are there are 100 percent out of harm's way,'' the general said. Indeed, the Pentagon reported the first casualty of the military action on Sunday. Air Force Staff Sgt. John Campisi, a 30-year-old aircraft mechanic from Covina, Calif., was klled when he was hit by a truck on a darkened runway. While soldiers took up their stations in the Saudi deserts, the White House pressed forward with its economic isolation of Iraq. Secretary of State James A. Baker III said the United States would begin ``almost instantly'' to ``take measures that are necessary and proportionate in order to enforce the (United Nations) sanctions.'' Asked if the United States was mounting a naval blockade, Baker _ appearing on ABC-TV's ``This Week With David Brinkley,'' _ said: ``Let's simply say that we now have the ability, the legal basis for interdicting those kinds of shipments.'' He declined to use the word blockade. Bush, vacationing in Kennebunkport, Maine, said the U.N.-approved embargo ``gave us broad authority, working in conjunction with others, to do whatever is necessary to see no oil goes out.'' Asked if the United States would block shipments of food as well as oil, the president said, ``Just watch. Everything.'' The Washington Post today quoted a senior administration official as saying, ``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.'' The U.S. pledge to stop the flow of goods in and out of Iraq came after Kuwait's exiled leader, Sheik Jaber Alahmed Al-Saba, asked that the United States take steps to ensure the U.N. economic sanctions take hold. As the Bush administration vowed to quarantine Iraq, Saddam, in a statement read by a spokesman on television in Baghdad, urged his people to prepare for hardships that may result from the international economic sanctions. He also linked any Iraqi withdrawal from Kuwait to an Israeli withdrawal from the occupied West Bank and Gaza Strip and a Syrian withdrawal from Lebanon. Israel seized the occupied territories from Egypt and Jordan in 1967. The White House ``categorically'' rejected Saddam's proposals, press secretary Marlin Fitzwater said, calling them ``another attempt at distracting from Iraq's isolation and at imposing a new status quo.'' Only the unconditional withdrawal of Iraqi forces from Kuwait will satisfy the United States, he said.