The Pentagon pays an average of $400 to put a gallon of fuel into a combat vehicle or aircraft in Afghanistan.

The statistic is likely to play into the escalating debate in Congress over the cost of a war that entered its ninth year last week.

Pentagon officials have told the House Appropriations  Defense Subcommittee a gallon of fuel costs the military about $400 by the time it arrives in the remote locations in Afghanistan where U.S. troops operate.

“It is a number that we were not aware of and it is worrisome,” Rep. John Murtha (D-Pa.), the chairman of the House Appropriations Defense panel, said in an interview with The Hill. “When I heard that figure from the Defense Department, we started looking into it.”

The Pentagon comptroller’s office provided the fuel statistic to the committee staff when it was asked for a breakdown of why every 1,000 troops deployed to Afghanistan costs $1 billion. The Obama administration uses this estimate in calculating the cost of sending more troops to Afghanistan.