The chief watchdog for Afghanistan reconstruction warned in a recent audit that the Pentagon is moving forward with a $772 million purchase of aircraft that the Afghan army "cannot operate or maintain."

The latest quarterly report from the Special Inspector General for Afghanistan Reconstruction cited the aircraft purchases among its top concerns. The IG's office had earlier issued a report in June detailing how "the Afghans lack the capacity -- in both personnel numbers and expertise -- to operate and maintain" existing and planned fleets.

The findings are likely to contribute to the budget debate on Capitol Hill over the funding. The bulk of the purchase is a $554 million contract for 30 Mi-17 helicopters from Russian firm Rosoboronexport.

Senators already are trying to strip funding for those contracts, out of concern for the company's ties to the government of Syrian President Bashar Assad. Before Congress went on recess, a Senate budget panel signed off on a spending bill that guts funding for the Mi-17 choppers.

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The IG audit cited a different set of concerns -- that the Afghan unit responsible for the aircraft has just one quarter of the personnel it needs to be at "full strength," that recruiting and training challenges inhibit growth; that the Afghan Ministry of Defense and Ministry of Interior have no agreement on the "command and control" of the unit; and that few of the pilots in the unit are fully qualified to fly with night vision goggles.

The report urged the U.S. military to suspend contracts until the Afghan ministries come to an agreement. It also called for a better plan to be developed for transferring the unit over to the Afghans.