RIYADH, Saudi Arabia -- The presence of Iraqi President Saddam Hussein's forces on the Kuwaiti border has heightened economic and security anxieties in neighboring Saudi Arabia.


As they were four years ago, rulers of this desert kingdom are deeply troubled by the strategic implications of allowing Saddam to move troops in an area only a few hours' drive from Saudi Arabia's Eastern Province, the sandy expanse that embraces more than 80 percent of the nation's industry and houses nearly a quarter of the world's known oil reserves.


But now the Saudi leaders must also worry about something new: the costs of supporting tens of thousands of U.S. soldiers.


Senior Saudi officials declared today that the kingdom would marshal whatever funds are necessary to deter aggression from Iraq. "Money is not the issue,'' said one. "The issue is Saddam.'' The Saudi government, he added, assumed from the instant it received word Iraqi troops were gathering on the Kuwaiti border that Riyadh would bear primary responsibility for funding the campaign to hold Saddam in check.


Still, the Iraqi encroachment comes at a terrible time for the Saudi nation. Although it rests above the world's richest field of petroleum, the desert kingdom is just now coming to grips with the cash-flow difficulties created by its hefty contribution to the 1991 war with Iraq.


The Saudi government shelled out a staggering $55 billion in a single year -- by far the largest financial contribution of any member of the Persian Gulf coalition -- for that campaign. Some Saudi economic planners estimate the war's total cost to the Saudi economy at more than $150 billion, a sum exceeding the nation's total domestic product.


That expense, combined with the effects of weak oil prices, has put a severe strain on the nation's public finances. Earlier this year, King Fahd called for an unprecedented 20 percent cutback in government spending. Riyadh has also moved to reschedule repayment of several major U.S. defense and aircraft contractors to ease its cash flow problems.


Only a week ago, Treasury Secretary Lloyd Bentsen visited the Saudi monarch at his expansive summer palace in Jiddah to cheer the Saudi budget-cutting effort -- and urge the king to push for still deeper retrenchment.


Representatives from United States and Saudi Arabia have had extensive discussions over the last several days about how to allocate the costs of resisting Iraqi troops, according to officials who participated. One U.S. official said Saudis expressed concern about the price tag attached to a massive show of U.S. firepower in the gulf. The official also said Saudi representatives had suggested that the government of Kuwait be asked to take on a greater share in fighting Saddam this time.


But a Saudi official familiar with the deliberations disputed that version of the discussions. "For us, the question has never been how much will it cost. It is how much (firepower) can you send us and how fast can you get it over here.''


Financial considerations may factor into the coalition's calculations about whether to let Saddam withdraw his troops without reprisal or to launch aggressive measures aimed at preventing Iraq from threatening Kuwait again. A preemptive strike against Saddam, or an offensive into Iraqi territory designed to create a wider buffer zone between Iraq and Kuwait, some Saudi officials argued, would be preferable to a long, expensive standoff in which the United States was obliged to deploy a larger defensive force along the border.


One Saudi official estimated that it has cost Saddam as little as $2 million to move his troops to the Kuwaiti border, while the expense to the gulf coalition of mustering a counterforce exceeded several hundred million dollars. "There is no question that Saddam must be punished,'' the official said. "Otherwise, there is nothing to stop him from pulling these stunts again and again.''


The problem for Riyadh is hardly that it will run out of money. At current rates of production, Saudi oil reserves will hold out well into the next century. Rather, it is that repeated confrontations with Iraq may force the government to reshape its economic model at a faster pace than it can handle.