Updated

The Department of Defense has pledged to closely monitor Afghan active-duty security forces so that U.S. taxpayer money is not squandered on so-called "ghost" soldiers, Stars and Stripes reported.

In a letter released Friday to the Pentagon, the office of the Special Inspector General for Afghanistan Reconstruction, or SIGAR, said it was concerned about "significant gaps between the assigned force strength of the (Afghan National Defense and Security Forces) and the actual number of personnel serving."

The letter, obtained by FoxNews.com, cites reports indicating discrepancies between the assigned force strength of the ANDSF and the actual number of personnel serving.

It also raises questions over whether the U.S. government is trying to prevent taxpayer funds from being spent on "ghost" soldiers and police -- particularly in Helmand Province.

SIGAR claims that since 2002, Congress has appropriated more than $68 billion in support of the ANDSF, including funding for ANDSF salaries.

Helmand’s incoming police chief said in June that close to half of the 26,000 soldiers and police officers assigned to that province did not exist, according to a June report by Afghanistan’s TOLOnews.

"In January 2015 we reported that more than $300 million in annual, U.S.-funded salary payments to the Afghan National Police were based on only partially verified or reconciled data, and that there was no assurance that personnel and payroll data were accurate," wrote John Sopko, Special Inspector General for Afghanistan Reconstruction.

"We found similar deficiencies during the course of our April 2015 audit of Afghan National Army personnel and payroll data," Sopko noted.

In response, the DOD said efforts were under way to verify the number of Afghan soldiers and police -- claiming roughly 90 percent of police and 70- 80 percent of soldiers have been biometrically enrolled, Stars and Stripes reported.

"When the initial inventorying is completed in July 2017, DOD and the Afghan (Defense Ministry) will have a more accurate representation of actual force strength," the Pentagon said, according to the newspaper.

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