The White House announced the first batch of military aid for Ukraine this year, more than three months after running out of money to replace the weapons it sent.

National security adviser Jake Sullivan said the U.S. will use a surprise $300 million in savings it found while buying supplies for Kyiv. The package will fund ammunition, anti-aircraft missiles, anti-tank weapons and artillery rounds, including for the High Mobility Artillery Rocket System, or HIMARS.

“This ammunition will keep Ukrainians’ guns firing for a period, but only a short period,” Sullivan said during a briefing.

The Defense Department used the last of its money to replace what it sent Ukraine near the end of last year and has been searching for ways to support the war effort ever since. Those include having other countries transfer weapons to Kyiv that Washington then replaces, rerouting weapons seized from Iranian smugglers and even perhaps using the last $4 billion in authority it has left to arm Ukraine.

That last option would sap American stockpiles since there isn’t any money left to refill them. One of the officials briefing reporters said this isn’t under consideration at the moment.

“We’re not considering any further drawdown packages at this time,” the official said.

The Defense Department’s offset for this aid is in some ways a sign of the situation in Ukraine. Since last fall, the administration has asked Congress for a massive infusion of money to support Ukraine, Israel and partners in the Pacific region. The Senate passed a version of that bill earlier this year. But the House hasn’t, and won’t consider its own version until after passing its long-delayed annual spending bills.

In the meantime, Ukraine has lost territory. Russia seized the eastern city of Avdiivka in February. Along some parts of the front line, Russian forces can fire eight to 10 artillery rounds for every one that the Ukrainian military can fire back, Lithuanian Defence Minister Arvydas Anušauskas said in an interview with Defense News.

The Pentagon has found savings of this sort before, the two U.S. defense officials said. About 6% of all the money Congress approved for Ukraine in the last two years was eventually refunded, the first official explained, adding that it was less noticeable before since the other funds hadn’t run out.

“We certainly can’t count on this as a way of doing business,” the official said.

As examples, the second official mentioned two sets of weapons: 25mm ammunition and Joint Light Tactical Vehicles. With both of these, the Pentagon was either able to buy them at a high enough number to lower the per-unit cost and save money or negotiate a lower cost with the company selling them. The upshot was a lower-than-expected bill, freeing up more money to offset aid to Ukraine.

Notwithstanding, the department has a much larger $10 billion bill for other weapons given to Kyiv in the last two years. That price tag is the result of the Pentagon underestimating how much it would cost to replace what it donated Ukraine. When Russia’s full-scale invasion started in February 2022, the first official said, the U.S. didn’t know how much more expensive it would be to buy new versions of the weapons it sent. It started by assuming the replacements would cost 10% more.

By the second half of last year, the official said, the Pentagon had better data and realized it was closer to a 20% hike.

Hence Pentagon leaders have been pleading for Congress to pass the supplemental spending bill. This new package, Sullivan said, may only last two weeks.

Noah Robertson is the Pentagon reporter at Defense News. He previously covered national security for the Christian Science Monitor. He holds a bachelor’s degree in English and government from the College of William & Mary in his hometown of Williamsburg, Virginia.

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