The opening week of the war against Iran has cost the United States more than $11.3 billion, lawmakers were told in a Pentagon briefing, according to a report by The New York Times that underscores the pace at which the conflict is consuming weapons and resources.

Citing unnamed sources familiar with Tuesday’s closed-door briefing, the newspaper said members of Congress were told the figure excludes many costs linked to the military buildup before the strikes—suggesting the final tally for the first week could rise substantially.

Defense officials had earlier told Congress that roughly $5.6 billion worth of munitions were expended in just the first two days of fighting, according to U.S. media—a burn rate far higher than earlier public estimates. Administration officials have also told lawmakers that the same $5.6 billion worth of munitions was used during the first two days of strikes.

Several congressional aides say they expect the White House to soon submit a request to Congress for additional funding for the war. Some officials say the request could reach $50 billion, while others believe even that estimate may prove too low.

So far, the administration has not provided a public assessment of the overall cost of the conflict or a clear indication of how long it may last. Donald Trump said during a trip to Kentucky on Wednesday that “we won” the war but added that the United States will remain in the fight to finish the job.

The campaign against Iran began on February 28 with U.S. and Israeli airstrikes and has so far killed around 2,000 people, mostly Iranians and Lebanese. The conflict has since spread into Lebanon, throwing global energy markets and transport into turmoil.

Members of Congress—who may soon have to approve additional funding—have expressed concern that the conflict could deplete U.S. military stockpiles at a time when the defense industry is already struggling to keep up with demand.

Against this backdrop, Donald Trump met executives from seven defense contractors last week as the Pentagon worked to replenish supplies.

Meanwhile, Democratic lawmakers have demanded public testimony under oath from administration officials about the Republican president’s plans for the war, including how long the conflict might last and what the strategy for Iran will be once the fighting ends.