Washington (AP) The Pentagon says the U.S. military is spending about $153 million a month in Iraq on fuel.

Including, gasoline, diesel and jet fuel, the military is burning through more than 50 million gallons of fuel a month in Iraq.

Some members of congress are upset because that cost is coming at a time when Iraq itself is looking at a potential oil boom this year. The U.S. Special Inspector General for Iraq says Iraq's oil revenue could approach $60 billion.

Democratic Senator Carl Levin of Michigan and Virginia republican John Warner are calling for an investigation of how Iraq's government is handling its money. In a letter to the government accountability office, the senators question why taxpayers are footing a big part of the cost of basic services and reconstruction in Iraq's at a time when it's earning billions from oil.