NEW YORK, JAN. 20 -- The Bush administration today escalated pressure on Japan and Germany to make substantial additional contributions to the cost of Desert Storm, hoping to head off possible criticism that it failed to extract a fair share of the financial burden from our richest allies.

In advance of a meeting beginning tonight among the finance ministers and central bankers of the Group of Seven, Treasury Secretary Nicholas F. Brady asked Japanese Finance Minister Ryutaro Hashimoto for a commitment greater than the $2 billion Japan earlier had agreed to donate for military assistance. Of the $2 billion, about half has been delivered.

Brady said "they said that they would do their share," but the secretary refused to indicate the exact U.S. demand or the extent to which the Japanese minister agreed to the demand. However, other sources said Brady was pleased with the outcome of the meeting. Japan earlier had pledged $2 billion for economic aid to the "front-line" nations of Egypt, Turkey and Jordan.

Similar demands for greater financial assistance will be placed by Brady before German finance minister Theo Waigel tonight or tomorrow at a breakfast meeting, depending on the time of Waigel's arrival in New York. The German minister was delayed by mechanical problems of his aircraft, which forced an unscheduled landing in Newfoundland.

Japan and Germany already have been broadly criticized by members of both American political parties in last weekend's debate on war powers for President Bush because of what congressmen alleged were inadequate contributions to the gulf effort and for delays in making commitments against their pledges.

The German government, which had pleaded that it is undergoing extraordinary demands on its resources for the cost of unification with the former state of East Germany and for aid to other Eastern European countries, already has promised $1 billion in military help, of which at least two-thirds has been delivered. Like Japan, Germany has pledged $2 billion in assistance for the front-line countries.

Brady conveyed to Hashimoto today the strong feeling within the Bush administration that the American public will consider it unacceptable if its allies do not assume a major share of the monetary cost of Desert Storm, inasmuch as the United States is providing the great bulk of the manpower and is likely to take the largest number of casualties.

Overall, including $3 billion from Japan and Germany, U.S. allies have undertaken to pay about $10 billion for the military costs of operations in the gulf, or about one-third of the $35 billion that was the estimated cost before fighting broke out Wednesday.

The earlier costs of the war effort have been estimated at $1 billion to $3 billion a month. The costs of a shooting war now are estimated at $500 million to $1 billion a day. At that level, said Robert Hormats, vice president of Goldman Sachs & Co., America's allies should pick up two-thirds of the total cost, divided equally between industrial nations such as Japan and Germany, and the friendly Arab oil producers.

"If the United States accepts the bloodshed, the others ought to take that much of the financial burden. That's reasonable," Hormats said.

The two-day G-7 meeting, which brings the principal Western allies together, is the first opportunity for the burden-sharing issue to be discussed since the onset of the war.