One week after an international military coalition intervened in Libya, the cost to U.S. taxpayers has reached at least $600 million, according figures provided by the Pentagon.
U.S. ships and submarines in the Mediterranean have launched at least 191Tomahawk cruise missiles from their arsenals, costing $268.8 million, the Pentagon said.
U.S. warplanes have dropped 455 precision guided bombs, costing tens of thousands of dollars each.
A downed Air Force F-15E fighter jet will cost more than $60 million to replace.
And operation of ships and aircraft, guzzling ever-more-expensive fuel to maintain their positions off the Libyan coast and in the skies above, could reach millions of dollars a week, experts say.
"Each sortie, even if it drops no munitions, is very pricey," said Winslow Wheeler of the Center for Defense Information. "These airplanes cost us tens of thousands of dollars to operate per hour, and the fancier you get in terms of planes, the costs get truly astounding."
The three B-2 stealth bombers that flew from Missouri to Libya and back on an early bombing mission each cost an estimated $10,000 per hour to fly, a defense official said.
That means the planes, each on a 25-hour round-trip flight, ran up a bill of $750,000, and the 45 Joint Direct Attack Munitions (JDAM) they dropped added at least $1.3 million more.
So far the Pentagon has financed the mission to take out Libyan leader Moammar Gadhafi's air defenses and disrupt his attacks on opposition forces using money in its existing budget, which has room for unanticipated military actions. The White House has not been forced to ask Congress for additional funds for the campaign.
Service member salaries, fuel costs and equipment maintenance are all part of annual military operating budgets. And hundreds of munitions, including the $1.4 million cruise missiles, are acquired each year and routinely used in action and training, officials say.
But experts say the administration may have to submit an emergency supplemental budget request for Libya later this year, assuming U.S. involvement in the international military operation does not end swiftly.
The cost of operating the no-fly zone over Libya alone could cost the U.S. an estimated $30 million to $100 million a week, a study by the Center for Strategic and Budgetary Assessments found.
While many Republicans and Democrats on Capitol Hill have questioned President Obama's constitutional authority to engage in Libya without their consent, some are voicing concern about the effect on the skyrocketing federal deficit.
"We have already spent trillions of dollars on the wars in Iraq and Afghanistan, both of which descended into unwinnable quagmires," Democratic Rep. Dennis Kucinich of Ohio wrote in a letter to colleagues last week. "Now, the president is plunging the United States into yet another war we cannot afford."
The wars in Iraq and Afghanistan have together cost more than $1.2 trillion so far, excluding troops' pay, medical costs and interest payments on debt incurred, according to the National Priorities Project, a nonprofit budgetary research group.
More than 5,800 American military service members have been killed in Operation Enduring Freedom and Operation Iraqi Freedom since 2001.
Kucinich wants the House to vote to cut off funding for the Obama administration's military action in Libya, which he has suggested could be an impeachable offense.
Meanwhile, Obama has defended his decision to intervene in Libya, saying the mission is in support of an "international mandate" with a limited, humanitarian scope. The president has also said the U.S. military would only be actively involved for "days, not weeks" before other allied partners take on a leading role.
But Sen. Richard Lugar of Indiana, the top Republican on the Senate Foreign Relations Committee, and many of his peers say regardless of the president's intentions, the costs to taxpayers -- and potentially in American lives -- coupled with an uncertain outcome make the military intervention unwise.
"It's a strange time in which almost all of our congressional days are spent talking about budget, deficits, outrageous problems. And yet same time, all of this passes -- which is a very expensive operation even in a limited way, always is," Lugar said last week.