The Pentagon says it overestimated the value of weapons sent to Ukraine over the past two years by $6.2 billion. That number more than doubles early estimates that were reported in May. The surplus will now be used for future aid to the embattled country. 

“In a significant number of cases, services used replacement costs rather than net book value, thereby overestimating the value of the equipment drawn down from U.S. stocks and provided to Ukraine,” Pentagon spokeswoman Sabrina Singh said at a news briefing on June 21. 

The final calculation of the accounting error is far higher than the Pentagon previously estimated in May, when it first revealed the miscalculation as $3 billion. According to the Pentagon’s final calculations, there was an error of $2.6 billion in the 2022 fiscal year and $3.6 billion in the 2023 fiscal year. As a result, the department now has additional money to use to support Ukraine.

“It’s just going to go back into the pot of money that we have allocated for the future of Pentagon stock drawdowns,” Singh said. 

The $6.2 billion is likely to mitigate the need for Congress to pass an additional assistance package before the end of the fiscal year in September.

Congress approved the latest round of aid in December, totaling roughly $45 billion for Ukraine and NATO allies. While the package was designed to last through the end of September, some are concerned that the funds could run out by mid-summer. But much depends upon the events on the ground in Ukraine. 

The Pentagon has repeatedly used presidential drawdown authority to pull weapons, ammunition and other supplies off the shelves for Ukraine. The presidential drawdown provides quicker assistance to Ukraine then the traditional process of purchasing supplies would be.

Officials have not been able to give exact totals for the amount of money that remains for the drawdowns or for the Ukraine Security Assistance Initiative, which provides longer-term funding to purchase weapons like larger air defense systems. 

The accounting error announcement comes amid Ukraine’s long-awaited counteroffensive to regain occupied territories, which requires significant financial support. The aim is to push out Kremlin forces from territory Ukraine forces occupied since Russia’s full-scale invasion in February 2022. 

Officials said Ukrainian air defenses downed 32 of 35 drones that were launched by Russia June 20. Kyiv has been under attack by exploding drones, which has exposed gaps in Ukraine’s air protection. 

The U.S. has approved four rounds of aid, around $113 billion, to Ukraine for their war efforts. Some of the money is going towards replenishment of U.S. military equipment that was sent to the frontlines. Using the new calculation, the U.S. has provided less than $34 billion in aid. Singh said the accounting mistake will not affect the ongoing delivery of aid to Ukraine. 

President Biden, and his senior national security leaders, have repeatedly stated that the United States will help Ukraine “as long as it takes” to repel Russian forces.