Department of Defense officials are giving two cargo planes worth more than $100 million to Afghanistan's air force, even though they may not be needed.

The Afghan Air Force already "underutilizes" two of the C-130 cargo planes it previously received from the U.S. Air Force, according to the Special Inspector General for Afghanistan Reconstruction.

The two planes — which were delivered to Kabul, Afghanistan, in October — flew at only 48 percent capacity last year, according to SIGAR.

Thus, the Afghan Air Force may not need the two additional C-130s it will receive next month, SIGAR said.

Despite being told the C-130 would be "too complex and costly for the Afghans," the deputy secretary of defense directed the U.S. Air Force to turn them over them, according to SIGAR.

Pending a review of the Afghan Air Force's requirements — which have not been updated in four years — DOD should "delay delivery of additional C-130s," SIGAR recommended.

The elimination of one C-130 could save taxpayers up to $40.5 million through 2017, according to SIGAR.

"Action now could save substantial expenditures," SIGAR said.

The C-130 is often used for "air-dropping troops and equipment into hostile areas," according to the Air Force.