KENNEBUNKPORT, MAINE, AUG. 18 -- President Bush today condemned as "totally unacceptable" Iraqi threats to use Americans and other foreign nationals as a shield to forestall U.S. military action and said it was "contrary to all accepted norms of international conduct" to threaten to withhold food from the trapped citizens, especially children and the elderly.

In a statement issued by White House press secretary Marlin Fitzwater here, Bush was described as "deeply troubled" by the new threats that Americans and others would be relocated "against their will" and "deeply concerned" by the newest Baghdad warning that if food supplies shrink as a result of the international economic embargo against Iraq, the Americans and others would suffer too.

"The use of innocent civilians as pawns to promote what Iraq sees to be its self-interest is contrary to international law and indeed to all accepted norms of international conduct," Fitzwater said.

Meanwhile, the State Department said it still could not confirm the location of 35 Americans taken Friday from the Hotel al-Rashid in Baghdad, although officials have said they believe the Americans were moved to another hotel.

A State Department official said the U.S. Deputy Chief of Mission in Baghdad, Joseph Wilson, was in "continual contact" with the Iraqi Foreign Ministry concerning the welfare of the Americans and demanding access to the 35 who were taken from the hotel. "In every conversation with an Iraqi official, we remind the Iraqis of their responsibility for the welfare of the Americans and other foreigners in Iraq and in Kuwait," said State Department press officer Nancy Beck.

Iraq's Ambassador to the United States, Mohamed Sadiq Mashat, was summoned to the State Department again today where Deputy Assistant Secretary David Macke reiterated concern for the missing Americans, Beck said. In addition, she said, in Kuwait the U.S. Embassy has been keeping in touch with Americans. Earlier this week, Iraq ordered the Americans in Kuwait to report to hotels, but most did not. "We remain deeply concerned about any reports that Americans in Iraq and Kuwait might be moved," Beck said. "We cannot confirm any attempts to round up Americans." About 2,500 to 3,000 U.S. citizens are estimated to be in Kuwait, including diplomats and private citizens employed in oil, business and banking, and their families.

The U.S. protests came during an escalating war of nerves between the United States and Iraq in which the rhetoric used by the two countries has become increasingly hostile and personal.

The White House has consistently maintained a low-key approach to the question of Americans who are trapped in Iraq and Kuwait in an effort not to raise their value to the Iraqis during the conflict. But the quick reaction by the White House today to the latest Iraqi warnings suggested increasing concern about the stalemate in the Persian Gulf and the fate of the Americans and others who cannot get out.

The White House urged Iraq to "immediately reconsider" its refusal to allow foreign nationals to leave Iraq and Kuwait "without delay or condition" and said the United States would begin urgent consultations with other affected governments to determine "what additional measures ought to be taken."

The White House also announced that Bush would move up his scheduled return visit to Washington on Sunday to convene a dinner meeting of his national security advisers that evening at the White House.

During an early morning round of golf with his son George at the Cape Arundel Golf Course in Kennebunkport, Bush refused to answer reporters' questions about the deepening crisis. "I'm not going to take any more comments up here," he said, the first time he has failed to respond to shouted questions from the press during his several rounds of golf here.

"I just don't like taking questions on serious matters on my vacation," Bush said later during the round, a note of irritation in his voice. "It just doesn't seem appropriate" to answer questions while golfing, "so I hope you'll understand if I -- when I'm recreating, {I} will recreate. And then when we're working, which I'm trying up here, I'll work hard."

Today's developments came as the administration readied plans to call up reserve units to supplement the active duty forces already en route to Saudi Arabia and the gulf region. Pentagon officials expected to finish the details in a day or two, sources said.

One sign of the administration's serious view of the deployment effort was its decision late Friday to activate the Civil Reserve Air Fleet (CRAF), composed of planes from the U.S. commercial airline industry that must be turned over to the government within 24 hours for shipments of men and materiel to the Persian Gulf.

Before the decision, a senior military official said in an interview that activation of the fleet would be an important sign that the United States contemplated, or feared, military conflict. The civil reserve fleet, which has never before been activated, was created for circumstances where U.S. military force must be invoked under extraordinary time pressures.

"We'd call on the CRAF if we felt that we couldn't afford to give Saddam a lot of time" to take provocative action, the official said on condition that he not be identified.

Balz reported from Kennebunkport, Hoffman from Washington. Staff writer R. Jeffrey Smith also contributed to this report.