WASHINGTON (AP) _ The latest installment of the U.S. bill for the Persian Gulf War is $32.2 billion, of which more than $3 billion will come from American taxpayers because the allies have not yet fully delivered promised aid, the chairman of the Senate Appropriations Committee said Thursday.

The price tag will grow by an unknown amount, probably tens of billions of dollars. The $32.2 billion is only part of what the war and its aftermath are expected to cost, according to administration figures released by the chairman, Sen. Robert Byrd, D-W.Va.

The numbers were the first cost update since Congress passed war-financing legislation last month requiring regular reports from the administration on expenses and foreign contributions.

A separate bill last year provided an initial $1 billion toward the U.S. troop deployment, Operation Desert Shield.

Many members of Congress have been critical of America's allies for being slow to deliver their promised aid.

The war-costs bill included a ban on arms sales to nations that still owe promised payments. But the measure gave President Bush leeway to continue weapons deliveries to countries in the process of paying the pledged aid.

So far, six countries have paid just under $29 billion in cash.

The United States is using those funds to pay the bulk of the latest war bills. The rest, more than $3 billion, is coming from some $15 billion in federal money provided in the war-financing legislation signed by President Bush on April 10.

Overall, six countries pledged to give the United States $54.6 billion for its war costs. They delivered $33.8 billion as of April 12 - about $29 billion in cash and nearly $4.8 billion in goods and services.

''We expect our allies to pay their fair share, and at least to pay what they pledged to pay,'' Byrd warned on the Senate floor.

Byrd said the $32.2 billion figure submitted by the Defense Department did not include the costs of actual combat or the replacement and repair of some equipment lost during the fighting.

No one knows what the final bill will be, Byrd said. But he noted that the administration initially estimated that the costs of the war and removing troops and equipment from the Middle East would be $68.5 billion.

Under the war-costs legislation, the $3 billion in taxpayers' dollars will be reimbursed when additional payments arrive from the allies.

Saudi Arabia pledged $16.8 billion, the largest amount, and has paid $7.6 billion, or 45 percent of the total, the figures showed.

In addition, Kuwait has paid $7 billion of its promised $16 billion, or 44 percent; Japan has paid $9.4 billion of its $10.7 billion pledge, or 87 percent; and Germany has delivered practically all of its $6.6 billion pledge. Also, the United Arab Emirates have paid $3.1 billion of a promised $4 billion, or 77 percent; and South Korea has sent $154 million of its pledge of $385 million.