The United States has spent more than $3 billion on the military campaign against the Islamic State in Iraq and Syria (ISIS), the Pentagon said in an update Monday.

The U.S. has spent $3.21 billion as of July 15, spokesman Bill Urban said. Since the campaign against ISIS began on Aug. 6, the military operations have cost an average of $9.4 million per day.

A bulk of the money, 53 percent, has been spent on airstrikes, according to the Defense Department. Just under a quarter of the money has been spent on weapons, with the rest spent on missions involving military carriers and other operations.
The average daily cost of the ISIS campaign has risen since September, ticking up to $9.9 million a day after costing around $5.6 million per day in the first few weeks.

The United States began launching airstrikes against ISIS in Iraq last August after the group seized large swaths of territory and began carrying out brutal executions of Americans and other captives.

The military expanded to Syria in September.

The cost of the ISIS fighting crossed the $1 billion mark in December and the $2 billion mark in April.