Updated

The military campaign in Iraq (search) has cost the Pentagon (search) about $48 billion so far, a number expected to rise by $10 billion by the end of September, the military's budget chief said Tuesday.

Dov Zakheim, the Defense Department's comptroller, said in an Associated Press interview the estimated cost so far includes the combat phase, which started March 20, postwar stabilization efforts and $30 billion in prewar expenses such as moving troops to the region and building facilities there.

Although officials have receipts and actual costs only through April, they believe the cost of the military's part of the campaign beginning in January is averaging $3.9 billion a month.

Some two months into stabilization efforts, Zakheim said he cannot yet estimate reconstruction costs for next year because the size of the future U.S. military presence needed there remains unclear. The picture will be clearer once international troops arrive to help with peacekeeping, he said.

"By the end of September, we will see additional forces, ... will see the state of the country," he said. "Then we'll be in a better position to estimate."

Gen. Tommy Franks (search) said last week that U.S. forces in the area will stay about the same size for the "foreseeable future."

In April, Congress approved an extra $62.6 billion for the Pentagon, which already had a budget of $364 billion for the current fiscal year. The new money was for the war in Iraq and the global war on terror.

Zakheim said he expects all but $4 billion of that will be needed this fiscal year, which ends Sept. 30.

The estimated monthly average of $3.9 billion includes $1.1 billion in salaries for reservists called to active duty; $2.6 billion for such requirements as logistics and transportation; and $200 million for food, health costs and other support.

Over the nine months, that $3.9 billion average comes out to $35 billion. It doesn't include replacement of damaged equipment and replenishing munitions and other materiel consumed in the war. Those expenses amount to a further $23 billion, for the total $58 billion expected by year's end, Pentagon calculations show.

It also doesn't include salaries of active duty soldiers, sailors and airmen, who would be paid with or without war.

None of the figures include what has been spent on several hundred American civilians working since the end of the war as part of the occupation authority. They are from the State Department, Treasury, FBI and other agencies, which pay their salaries.