Pentagon Says Accounting Mistake Frees Up $3 Billion More for Ukraine

But they added that they had not yet determined whether the adjustment would result in a windfall of additional weaponry for Ukraine.

Lawmakers from both parties have repeatedly asked the administration how it intended to stretch its dwindling budget authority to supply Ukraine with weapons quickly — called presidential drawdown authority — without handicapping Kyiv’s efforts to mount a decisive counteroffensive against Russia this summer.

“I’m worried that it’s going to leave a gap,” Senator Susan Collins of Maine, the top Republican on the Senate Appropriations Committee, said in an interview Wednesday, before staff members were told about accounting revision. “I am concerned that the administration has not been forthcoming on how much more money they need, and at what period will the funds that we’ve appropriated run out.”

“They need to have the munitions they need and the capabilities that they need, and I think we need this big push this summer, to punch Putin in the mouth a few more times,” said Representative Elissa Slotkin, a Democrat from Michigan and a former C.I.A., State Department and Pentagon official who is on the House’s Armed Services Committee.

Presidential drawdown authority allows the administration to pull from existing weapons stocks, instead of waiting the several months or years it can take for defense contractors to manufacture weapons under new contracts. The Biden administration has highlighted the program as one of its signature achievements in helping Ukraine battle Russian forces.

Under drawdown authority, the administration decides which weapons to send out from existing stocks and how to determine their value. Since the start of the conflict, the Pentagon has announced a new drawdown package about every two weeks, with each valued in the hundreds of millions of dollars.

But according to the administration’s own calculations, its coffers had been running low. Congress approved $14.5 billion in drawdown authority to last through the fiscal year, which ends on September 30. As of Wednesday, according to congressional aides, only $2.7 billion of that was left. That is not enough, they said, to sustain the current pace and size of military aid packages without running out of funds by July or August.