WASHINGTON (Reuters) - The Iraq war may not dominate U.S. news reports as the carnage drops, but a new report underscores the financial burden of persistent combat that is helping run up the government’s credit card.

A U.S. soldier from 2nd Brigade combat team, 82nd Airborne Division stands guard near a shop which is closed during a patrol in Baghdad's Adhamiya district January 5, 2008. REUTERS/Mahmoud Raouf Mahmoud

“Funding for U.S. operations in Iraq and Afghanistan and other activities in the war on terrorism expanded significantly in 2007,” the Congressional Budget Office said in a report released on Wednesday.

War funding, which averaged about $93 billion a year from 2003 through 2005, rose to $120 billion in 2006 and $171 billion in 2007 and President George W. Bush has asked for $193 billion in 2008, the nonpartisan office wrote.

“It keeps going up, up and away,” Senate Budget Committee Chairman Kent Conrad said of the money spent in Iraq since U.S. troops invaded in 2003.

“We’re seeing the war costs continue to spiral upward. It is the additional troops plus additional costs per troop plus the over-reliance on private contractors, which also explodes the costs,” said Conrad, a North Dakota Democrat who opposed the war.

Since the September 11, 2001, attacks on the United States, Congress has written checks for $691 billion to pay for wars in Iraq and Afghanistan and such related activities as Iraq reconstruction, the CBO said.

There are around 158,000 U.S. troops in Iraq and 27,000 in Afghanistan.

$11 BILLION A MONTH

Of the total, the CBO estimated that $440 billion had been spent on fighting in Iraq launched with the goal of ousting President Saddam Hussein from power and securing weapons of mass destruction that were never found.

All of the Iraq and Afghanistan war money -- about $11 billion a month -- is effectively being put on a government credit card at a time when U.S. government debt has skyrocketed to more than $9 trillion, up from around $5.6 trillion when Bush took office in January 2001.

Bush has opposed paying the cost of waging war in Iraq and Afghanistan with tax increases or other specific offsets.

That means that nearly every penny spent gets added to the U.S. debt. The CBO estimated that just the interest payments on the debt would total $234 billion this year, more than the likely $250 billion budget deficit for the year.

These annual deficits and steep interest payments on borrowing all get rolled into the running tally that is the government’s debt -- the more-than-$9-trillion figure.

The debt problem snowballs long-term, especially if the escalating costs of government-run health care and retirement programs are not reined in and if the United States maintains a large long-term military presence in Iraq.

Interest payments on the debt will total an estimated $2.7 trillion over the next decade, the CBO said.

Congress is expected to pass another round of money for the war in May or June, despite repeated attempts by Democrats to bring the fighting in Iraq to an end.

Republicans have defended the costs of the Iraq war, saying it has helped to stave off new attacks on the United States.

But Conrad said the deficit spending on the war was “another negative trend among many negative trends” in the budget.