The cost of the air war in Libya for the US military has reached $608 million, a US defense official said on Monday.
The cost estimate covers the period from the start of international air strikes in Libya on March 19 to April 4, the official, who spoke on condition of anonymity, told reporters.
US officials previously had said the operation had cost $550 million through March 28.
The Pentagon has estimated the air campaign will cost the United States about $40 million a month, even after Nato allies took the lead in the UN-mandated operation designed to protect civilians against Moamer Kadhafi's forces.
For the US Air Force alone, the war costs about $4 million a day, the top civilian in the air force told reporters last week.
But Air Force Secretary Michael Donley said he expected that figure to come down with European allies carrying out bombing raids while US aircraft play a support role.