FIRST ON FOX: Senators J.D. Vance and Josh Hawley on Wednesday will introduce legislation aimed at preventing future "accounting errors" at the Department of Defense, after the Pentagon revealed it overvalued military equipment sent to Ukraine by more than $6 billion.

The bill clarify that when the Foreign Assistance Act’s presidential drawdown authority (PDA) is used to respond to an unforeseen emergency, the DOD must calculate the "aggregate value" of defense articles by using either the original acquisition cost to the U.S. government plus the cost of improvements or modifications made, or the cost of replacing these articles, whichever is greater.

The bill would also require the DOD to calculate the full cost to the U.S. government of providing defense services.

PENTAGON ACCOUNTING ERROR OVERESTIMATES VALUE OF WEAPONS SENT TO UKRAINE BY $6.2 BILLION

Republican Ohio Sen. J.D. Vance

Sen. J.D. Vance, R-Ohio, is proposing legislation aimed at eliminating future ‘accounting errors’ at the Pentagon. (Tom Williams/CQ-Roll Call, Inc via Getty Images)

"This legislation will save American taxpayers from footing the bill for shoddy accounting at the Pentagon," Vance, R-Ohio, told Fox News Digital.

"There should be no excuse for accounting errors with a seven-figure price tag," he said. "With this bill, Congress can ensure that the cost of our military aid is properly and consistently calculated."

Hawley, R-Mo., told Fox News Digital that the "so-called valuation errors around U.S. aid to Ukraine are a transparent attempt to bypass Congress for additional funds, while continuing to prioritize Ukraine over more vital U.S. interests, including deterring China in the Pacific."

US TO PROVIDE CLUSTER MUNITIONS TO UKRAINE, $800 MILLION MILITARY AID PACKAGE, OFFICIALS SAY

Pentagon

Pentagon officials said they miscalculated the value of aid delivered to Ukraine in both 2022 and 2023. (DANIEL SLIM/AFP via Getty Images)

"We must force the DOD to appropriately account for any future aid, not only for Ukraine, but also for all U.S. security assistance going forward," Hawley told Fox News Digital.

Under PDA, the president sends military equipment currently in DOD’s stockpiles abroad, and this process is currently being used to aid Ukraine. The use of drawdown authority instead of buying new weapons for Ukraine facilitates a speedy delivery of existing equipment in an emergency, although the move also depletes U.S. stockpiles.

Sources familiar with the planning for the legislation told Fox News Digital that Congress has chosen to limit PDA transfers by placing a monetary cap on their aggregate value. That means the higher the value of a weapon, the fewer the DOD can send, to Ukraine or elsewhere, before reaching the PDA cap.

VANCE DEMANDS BIDEN ADMIN TURN OVER 'FULL CROSSCUTTING' REPORT ON SECURITY ASSISTANCE PROVIDED TO UKRAINE

Sen. Josh Hawley

Sen. Josh Hawley accused the Pentagon of tweaking the numbers in order to justify sending more aid to Ukraine. (Bill Clark/CQ-Roll Call, Inc via Getty Images)

The bill was introduced after the Pentagon admitted last month that it overestimated the value of the weapons it has sent to Ukraine by $6.2 billion over the past two years — about double the early estimates.

Pentagon spokesperson Sabrina Singh said a detailed review of the accounting error found that the military services used replacement costs rather than the book value of equipment that was pulled from Pentagon stocks and sent to Ukraine. Singh said final calculations show there was an error of $3.6 billion in the current fiscal year and $2.6 billion in the 2022 fiscal year, which ended last Sept. 30.

As a result, the Pentagon says it now has additional money in its coffers to use to support Ukraine as it pursues its counteroffensive against Russia.

Congressional lawmakers are continuing to press the Defense Department to track aid being sent to Ukraine, but Pentagon officials say a "robust program" is in place to do so.

Volodymyr Zelenskyy

Ukraine's President Volodymyr Zelenskyy speaks with the media as he arrives for a NATO summit in Vilnius, Lithuania, Wednesday, July 12, 2023. (AP Photo/Mindaugas Kulbis)

Singh said the accounting error will not affect the U.S. delivery of aid to Ukraine.

Last week, the Biden administration provided cluster munitions to Ukraine and announced additional military aid worth up to $800 million for war efforts against Russia.

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The weapons will come from Pentagon stocks and will also include Bradley and Stryker armored vehicles plus an array of ammunition, such as rounds for howitzers and the High Mobility Artillery Rocket System, known as HIMARS, the officials said.

The Associated Press contributed to this report