Key legislators are urging other countries to contribute more money and commit more forces to the U.S.-led military operation in the Middle East, now that the United States has agreed to send up to 200,000 additional troops there to force an Iraqi withdrawal from Kuwait.

Without additional foreign contributions to the international coalition organized against Iraq, the legislators worry that congressional criticism of the gulf operation could intensify and result in a divisive domestic debate over military action to oust Iraq's forces.

Such concerns, voiced this week by the Democratic chairmen of the House and Senate Armed Services committees as well as other legislators, appear to have caught the Bush administration by surprise. Senior U.S. officials said yesterday they have no immediate plans to press the allies for additional contributions.

U.S. allies in Europe, Asia and the Middle East have so far pledged up to $20 billion to ameliorate costs of the Middle East crisis, with roughly $6 billion to defray U.S. military expenses in defending Saudi Arabia and enforcing the U.N.-sanctioned embargo of Iraqi trade, according to a tallies provided yesterday by the Defense and State departments.

Officials say the $6 billion contribution to the U.S. military operation represents only a fraction of the cost of deploying as many as 430,000 U.S. troops in the region by early next year. Legislators have expressed concern that this deployment leaves the United States carrying too much of the military burden.

House Armed Services Committee Chairman Les Aspin (D-Wis.) yesterday said that U.S. ground troops now amount to 57 percent of those deployed in Saudi Arabia. Officials said that without additional foreign troop deployments, the U.S. share will likely rise to more than 70 percent.

"If Americans are critical today of the relative unwillingness of others -- chiefly Europeans and Japanese -- to share the burden of this confrontation, imagine how critical, even furious, they are likely to be when they see few others paying the blood price," Aspin said in releasing a report critical of the allied contributions.

Senate Armed Services Committee Chairman Sam Nunn (D-Ga.) said, "I think there are serious questions raised when America has 70 to 80 percent of the forces in the region . . . . The last thing that we need in that part of the world is for it to appear to be {the} United States versus Iraq and perhaps even become U.S. versus Islam. We don't want that. It is not that now."

Nunn expressed concern that only several thousand Kuwaiti troops are on the front lines of the allied Western and Arab force, "particularly when they are seen on television demanding war and liberation immediately."

He also said Egypt, which has sent only one of the two divisions promised in August to Saudi Arabia, "ought to have a lot more forces there."

"This is not simply a military equation. It's psychological and political," Nunn said.

Other legislators raised similar concerns at a meeting with Secretary of State James A. Baker III and Defense Secretary Richard B. Cheney Wednesday, according to sources on Capitol Hill.

According to one person who attended the meeting, Baker said he expected that a number of other nations would increase forces in Saudi Arabia, but he did not name the countries or cite figures. A State Department official, speaking on condition of anonymity, said yesterday that he was "not aware of specific contributions" from other nations "tied to our new deployments."

At the Pentagon, spokesman Pete Williams said the U.S. military was satisfied with the contributions made by other countries so far. "I haven't heard any discussion of another trip {by U.S. officials} to go back and pass the hat one more time," he said.

Williams acknowledged that an earlier cost estimate of roughly $15 billion in fiscal 1991 for the Persian Gulf deployments "is clearly going to have to be revised" because it did not include the additional troops announced last week. He said a new estimate "will be out in a week or so."

Aspin's report praised Turkey and Egypt for strongly supporting the U.S. military operation while enduring economic losses estimated at more than $1 billion.

But Aspin described as "meager" the French and British pledges totaling roughly $50 million to defray economic costs of front-line Arab states harmed by the Iraqi trade embargo and oil price increases.

Aspin also complained that Japan had provided $600 million in "loans rather than grants" to front-line Arab states and was trying to ensure that "as much of {its pledged} money as possible is spent in Japan." He and other legislators have criticized Saudi Arabia for not pledging to give all its profits from oil price increases related to the crisis.

"Since Aug. 6, the Saudis have made billions of dollars more in higher oil prices . . . than what they have paid out to support the U.S. deployment," said Rep. Patricia Schroeder (D-Colo.), chairwoman of the Armed Services subcommittee on military installations and facilities.

"The front-line Arab states are not doing their part," she said.Staff writers Dan Balz and George C. Wilson contributed to this report.