WASHINGTON, March 10 (Reuters): U.S. President Donald Trump's administration said it used $5.6 billion in munitions during ​the first two days of strikes against Iran in a report provided to U.S. congressional committees, a source familiar with the information said on Tuesday.

Members of Congress, who may soon have to approve additional ​funding for the war, have expressed concern that the conflict ​will deplete U.S. military stocks at a time when ⁠the defense industry was already struggling to keep up with demand.

Trump met ​executives from seven defense contractors on Friday as the Pentagon worked ​to replenish supplies.

The administration has not provided a public assessment of the cost of the conflict it launched on Feb. 28 along with ally Israel.

Democratic ​members of Congress have clamored for more information, including public testimony ​from officials about issues including how the conflict might affect the U.S. military's ⁠to defend the country.

Administration officials have held several classified briefings for members of Congress and staff.

In a speech as he opened the U.S. Senate on Tuesday, Senator Chuck Schumer of New York, the ​Democratic leader, called ​on administration ⁠officials to appear before Congress.

"When it comes to sending our servicemembers into harm's way, the American people ​need to understand why. But right now, they ​don't ⁠even have a 'why.' That needs to change," Schumer said.

Several congressional aides have said they expect the White House to soon submit a request ⁠to ​Congress for additional funding for the war. ​Some officials have said the request could be for $50 billion, but others have said ​that estimate seems low.

Photo from Reuters