The US has spent more than $2.7bn on the war against Islamic State of Iraq and the Levant (ISIL) fighters in Iraq and Syria since bombings began last August, the Pentagon has said.
The average daily cost of the war is now more than $9m, the defence department said on Thursday as it released a detailed breakdown of the costs for the first time.
The data showed that the Air Force has borne two-thirds of the total spending, or more than $1.8bn, while the daily combat, reconnaissance and other flights cost more than $5m a day.
It also provided a rare look into the often secret special operations costs, which totaled more than $200m since August.
The release of the spending totals came as Congress debated and rejected legislation on Thursday that would have banned spending on the combat operations until lawmakers passed a new war powers resolution.
Military operations cost have grown since airstrikes began in Iraq in August, and then expanded to Syria the following month. The bulk of the strikes has been in Iraq, as the US and coalition strikes have tried to help Iraqi forces retake key and hold key cities.
Other costs include $438m for the Navy, $274m for the army, which has trainers and special forces troops on the ground, while $646m was spent on munitions among others.