The Pentagon said Monday that medical evacuation flights out of Iraq and Afghanistan are taking eight hours longer because of the cloud of volcanic ash hanging over Europe.

Pentagon spokesman Bryan Whitman said the military is using the Navy's Rota Air Base in Spain to fly troops back to the United States for care at Walter Reed Medical Center in Washington.

Typically, wounded troops are flown to Ramstein Air Base in Germany, where they can be transferred to the Landstuhl military hospital for treatment. But flights to Ramstein have been halted by a giant ash plume from last week's Icelandic volcano.

Whitman said the result has been an additional eight hours of flying time needed to get troops from the war zone to a first-class medical facility.

"While our southern flights take a bit longer, about eight hours, they have not had significant impact at this point," Whitman said.

"This is a temporary situation and our facilities and our ability to use other routes has proven to be effective," he added.