A US Air Force B-1 Lancer bomber on the tarmac at RAF Fairford in southwest England on March 11, 2026.

The administration of US President Donald Trump has estimated that the cost of the first six days of its ongoing war on Iran topped $11 billion, as the unprovoked war of aggression enters its 13th day.

Officials from the Pentagon said during a closed-door congressional briefing that they estimate the first six days of the war in Iran cost more than $11.3 billion, NBC News reported on Thursday.

The figure, it said, did not include the entire cost of the war, for which the US Congress may soon consider providing billions more in funding.

During the briefing, which was first reported by The New York Times, administration officials informed senators that $5.6 billion of munitions were used during the first two days of strikes.

Senator Chris Coons told reporters that he believes the amount is even higher.

"I expect that the current total operating number is significantly above that. If all you`re looking at is the replacement cost for the munitions used, it`s already well beyond $10 billion," Coons noted.

According to a number of congressional aides, the White House is expected to soon submit a request to Congress for additional funding for the so-called Operation Epic Fury.

Some officials believe that the request could be for $50 billion, while others have noted that such an estimate seems low considering the scale and intensity of the aggression.

During a trip to Kentucky on Wednesday, Trump claimed that he did not want war, but that the US would stay in the aggression to "finish the job."

The aggression has so far killed more than 1,400 Iranian civilians, including children.

According to US military figures, seven American troops have been killed in the war, and 140 others wounded, but Iranian officials have put the US death toll in three digits.

Members of the US Congress have already expressed concern that a full-scale war will deplete US military stocks at a time when the arms manufacturing industry is already struggling to keep up with demand.

Last week, Trump met with executives from seven arms contractors as the Pentagon worked desperately to replenish supplies.

As significant uncertainty surrounds the US war against Iran, lawmakers are pressuring administration officials to give public testimony under oath about Trump`s plans for the war - if he has any - including how long it might last.

This is while senior Iranian officials have already stressed that it is Tehran, and not Washington, that determines the end of the war.