A source told Reuters on Wednesday that officials from U.S. President Donald Trump’s administration reported during a briefing to Congress this week that the first six days of the war on Iran cost the United States no less than $11.3 billion.

Officials disclosed this figure during a closed session with Senate members on Tuesday. It does not reflect the total cost of the war but was presented to lawmakers who had requested more information about it.

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

The U.S. administration has not provided a general assessment of the war’s cost or a clear estimate of its expected duration. During a visit to Kentucky on Wednesday, Trump said, "We have won" the war, but added that the United States would continue the fight to complete the mission.

U.S. President Donald Trump (AFP.)

The "New York Times" was the first to report on the 11.3 billion dollar figure.

Additionally, U.S. administration officials informed lawmakers that $5.6 billion worth of ammunition was used during the first two days of the assaults.

Congress members, who may soon have to approve additional war funding, expressed concern that the conflict could deplete U.S. military stockpiles at a time when the defense industry is already struggling to meet demand.

Trump met last week with executives from seven defense industry companies as the Pentagon works to replenish supplies.

Democratic lawmakers have demanded that administration officials testify publicly under oath about the Republican president’s war plans, including how long it might last and his plans for Iran once the fighting stops.