President Bush said yesterday that he was willing to lend financial assistance to Jordan's King Hussein in order to ensure his compliance with the United Nations' embargo of Iraq, but the president also pointedly warned that U.S. warships could be forced to blockade Jordanian ports if they provide safe transit for Iraqi commerce.

Bush's blunt remarks on the eve of the Jordanian monarch's arrival in Washington for consultations with Bush and other senior administration officials indicated the importance the administration now attaches to closing the last major trade lifeline to Iraq.

The Red Sea port of Aqaba in southern Jordan has functioned in the past as a major trade route into Iraq. During the eight-year Iran-Iraq war, Iraq used about 70 cargo ships to haul weapons, food and other commodities to Aqaba, where they were offloaded onto trucks for the long desert road passage through Jordan to the Iraqi frontier.

The other seaborne approaches to Iraq in the Persian Gulf and to its oil pipeline terminals in Turkey and Saudi Arabia are under surveillance by U.S. and allied naval forces. But questions lingered yesterday over whether U.S. warship commanders had received any instructions from the White House on how to "interdict" Iraqi-bound shipping.

One administration official said a presidential directive proposed by the Pentagon was on Bush's desk but had not been signed. The official said the draft directive does not authorize American warship captains to fire their weapons to either warn or disable merchant ships bound to or from Iraqi ports. Rather, the directive instructs the military to turn back such shipping by verbal warning and aggressive maneuvering, the official said.

"It's the captain's call on whether to fire across the bow and that's where it gets real fuzzy," one military official said.

King Hussein's arrival was also significant because the king has just returned from Baghdad, where he held extensive discussions with Iraqi President Saddam Hussein Monday. Bush said he did not know whether the king was carrying a message from the Iraqi leader, whose armed forces overran Kuwait almost two weeks ago.

CBS News, citing unnamed Jordanian sources, said Hussein was carrying a letter from Saddam that called for a freeze on the U.S. military buildup in exchange for convening an international conference to discuss Iraq's withdrawal from Kuwait.

Bush interrupted his 23-day vacation in Maine to return to Washington for a White House meeting meant to highlight his impatience with congressional Democrats in budget negotiations. He spoke to reporters after meeting briefly with some of his budget advisers.

Meanwhile, it was not clear that oil-producing nations had complied with the Bush administration request to increase their output to make up for the more than 4 million barrels of crude oil per day that had been taken off the market by the embargo against Iraq and the loss of Kuwait's production. Bush said he remained confident that they would, but oil prices continued to inch upward, reflecting a tight market and pessimistic expectations about supply.

There also was no sign of any consensus in the Organization of Petroleum Exporting Countries to meet and raise production as part of the concerted effort to cooperate with the economic squeeze on Iraq.

As Bush spoke in Washington, thousands of U.S. troops continued to arrive at Saudi Arabian air bases, while Syrian forces were expected to join Egyptian and Pakistani troops who were on the ground.

Syria already had begun to move two Army divisions near its border with Iraq, according to U.S. officials.

The administration also appeared ready to provide Egypt with more than $1 billion in new F-16 fighters, Maverick antitank missiles and other weapons.

The international diplomacy in support of last week's 13 to 0 U.N. Security Council vote to shut down all commerce to Iraq until it withdraws its invasion force from Kuwait centered on two fronts.

First, officials from the United States, Europe and the Arab world were holding discussions on how to form a command structure for the ground troops, air and naval forces that are pouring into the region specifically to defend Saudi Arabia from an attack by the 140,000 Iraqi troops still massed in Kuwait.

But on a second front, the United States was still wrestling with the legal underpinning and international cooperation for a multinational force to effectively blockade Iraqi commerce. Bush made it clear in his news conference that the United States would proceed with its interdiction effort, but for the first time said he was willing to undertake talks with the Soviets and others about organizing a multinational naval force to enforce the U.N. embargo.

U.S. Navy officials traditionally have resisted any notion of putting U.S. ships under a multinational command.

"This is not the plan right now," Bush said, "but we are talking to see how we can make this naval presence most effective."

At the State Department yesterday, Undersecretary for Political Affairs Robert M. Kimmitt called a meeting of ambassadors of the five permanent members of the U.N. Security Council to consider how multinational naval forces might work in unison for possible action against Iraqi shipping.

The meeting followed Monday's closed-door discussions in New York by Security Council members in which at least four nations raised questions about the decision by the United States and Britain to use their naval power to enforce the U.N. resolution before the council has sanctioned such military steps.

Bush yesterday said the United States is within "our legal rights" to begin naval action under separate provisions of the U.N. charter that authorize collective self-defense. Bush has also said U.S. naval action is warranted by a request from Kuwait's deposed ruling family to block all shipping to and from Kuwaiti and Iraqi ports.

"We're doing it the way our attorneys and others around the world recommend," Bush said, "and I think we're doing it properly."

Bush, who criticized King Hussein's failure to condemn the Iraqi invasion last week, yesterday sought to throw a new diplomatic line to the monarch. "Clearly we have always been a friend of Jordan," Bush said. "We helped them in the past; we'd help them in the future if they fulfilled their obligations here."

Asked if he would help the king economically, Bush said, "I think we would, provided Jordan joined these other countries in fulfilling these obligations under the sanctions."

But at the same time, Bush said of Aqaba, "If it's a hole through which commerce flows in an otherwise tight net, I would certainly think that Aqaba should be closed to Iraqi commerce."

Calculating the impact of the embargo on Iraqi commerce dominated banking circles.

An International Monetary Fund (IMF) spokesman said yesterday that Iraq may have looted about $32 million worth of gold bullion and $800 million in foreign reserves cash, mostly dollars, from Kuwait's Central Bank and taken it to Baghdad. IMF officials also said Iraq may have looted an additional $1 billion from Kuwaiti commercial banks. Most of the gold and convertible cash of the sheikdom was deposited outside the country.

On the diplomatic front, yesterday's meeting at the State Department among ambassadors from the five permanent member states on the Security Council ended without action, but officials said afterward that the five agreed to continue working actively toward full implementation of the economic sanctions that the council imposed on Iraq last week.

In particular, the officials said, they agreed that their ambassadors at U.N. headquarters in New York should keep discussing a Soviet proposal that the Military Staff Committee of the Security Council be given some kind of role in controlling the naval buildup in the Gulf. They said Kimmitt proposed that the New York talks begin by the end of this week at the latest.

The military committee, a little-known adjunct of the Security Council that has been largely moribund during its 45-year existence, has taken on potentially great importance in the Gulf crisis because the Soviet Union said last week that it would not participate in any military activities unless they are under U.N. supervision.

The United States, which wants to confront Iraq with the broadest possible international opposition, is especially anxious to win Moscow's cooperation. Soviet Foreign Minister Eduard Shevardnadze discussed the military committee idea with Secretary of State James A. Baker III in a series of phone conversations during recent days, and State Department spokesman Margaret Tutwiler, noting that "this is a very different world we're starting in with the Soviet Union," said the United States is "very interested in pursuing their idea."

The committee's precise role, if any, in the Gulf situation must still be worked out, but U.N. sources have talked in general terms about such options as having all the warships in the Gulf operate under the U.N. flag, with the committee setting the rules under which they might interdict shipping to and from Iraq.

Staff writers John M. Goshko, Molly Moore and Steven Mufson contributed to this report.