WASHINGTON — The Pentagon has modified how it fulfills some training requirements for Afghan security forces in hopes it can renegotiate costs and needs that may become inaccurate over time, according to a U.S. government watchdog.

Prior to April 2019, most training requirements covered by the Afghanistan Security Forces Fund were filled under a single-award indefinite delivery, indefinite quantity contract. That approach, known as the Warfighter Field Operations Customer Support contract, provided the Defense Department with a broad range of support and a ceiling of $11.2 billion. But officials complained that the single-award contract limited the department’s ability to negotiate some costs.

“Only certain types of costs could be negotiated, such as those associated with housing, travel, and the number of advisers supporting the training,” the Government Accountability Office found.

Additionally, U.S. officials told the GAO that key decisions and associated cost assumptions related to training Afghan forces occur 18-24 months before the training actually takes place. That time frame, they said, can create a challenge in developing accurate cost estimates “given that situations in Afghanistan can change significantly.”

For example, the special inspector general for Afghanistan reconstruction reported in January 2019 that Combined Security Transition Command-Afghanistan — charged with supporting the Afghan National Defense and Security Forces — may have overestimated the cost for UH-60 Black Hawk pilot training by as much as $1 billion over a seven-year period. The possible overestimation was partly attributed to “unrealistic assumptions regarding student or pilot attrition and the English language program,” the GAO report said.

In response, the Defense Department began issuing new contracts involving multiple providers in April under an approach called the Enterprise Training Service Contract.

It “affords the opportunity to negotiate more elements than previously under the WFF contract, such as labor rates or travel costs associated with training,” the GAO said. The watchdog noted it is too soon to evaluate the effectiveness of this approach.

Since 2005, Congress has appropriated more than $78.8 billion for the Afghanistan Security Forces Fund to equip and train the Afghan National Defense and Security Forces, the GAO reported. Over that period, nearly $4.3 billion went toward training and operation support of the Afghan National Army.