International funding for Afghanistan's military and police forces is increasingly going directly to the Afghan government instead of through U.S. administrators, but the Department of Defense can't be sure the money won't be wasted by corruption and poor management.

The U.S. has promised at least $4.2 million in direct assistance to the Afghan National Security Forces Fund, which uses it to pay for salaries, food, minor construction and other expenses.

But DOD hasn't assessed whether the ministries in charge of managing that money are capable of handling it or whether officials can be trusted to spend it properly, according to a report by the Special Inspector General for Afghanistan Reconstruction.

"DOD cannot be assured that the funds provided directly to the Afghan government to fund and equip the ANSF are sufficiently protected and used as intended," Special Inspector General John F. Sopko wrote in the report, released Thursday.

Combined Security Transition Command-Afghanistan, the multinational group training the forces and overseeing their funding, does financial reviews of certain offices and transactions within the Afghan government.

But at least $453 million in direct assistance went unreviewed in 2013, according to SIGAR.

The transition command said staff shortages and heightened security prevented proper oversight. The office has only 40 employees, few of whom are trained auditors.

"According to one CJ8 official, 'You have to assume the data is sound; so it's simply a matter or looking for mistakes.' As a result, if fraudulent expenditures are properly coded within the accounting system, it is unlikely that CJ8 will identify the fraudulent activity," Sopko said.

Afghan accountants are also reluctant to use the more detailed codes that describe what money is spent on, Sopko said.

Command officials are also having a harder time visiting provincial offices since attacks on coalition advisers led to heightened security requirements.

Corruption isn't the only risk to U.S. and international funds. Literacy is a "systemic capacity gap" throughout Afghan ministries, command office officials told SIGAR.

"Reduced oversight leaves direct assistance funds particularly vulnerable to waste, fraud, and abuse. Because of the well-documented concerns about the Afghan government’s capacity to manage direct assistance funds, it is especially important for the United States to accurately assess the capacity of Afghan ministries to assume responsibility for U.S. direct assistance funds provided for the ANSF," he said.