One of the officials said the president’s comments referred to “existing funding authorities” Congress previously gave the administration “that allow us to provide additional support to Ukraine for a bit longer if Congress doesn’t act.”

One option under consideration is using foreign military financing — a program run by the State Department that provides grants or loans to help partner countries purchase weapons and defense equipment — intended for Ukraine and other countries impacted by Russia’s full-scale invasion, said the two officials.

As of Sept. 21, the U.S. had roughly $650 million remaining out of $4.6 billion in foreign military financing that Congress appropriated across two supplemental packages for Ukraine and “countries impacted by the situation in Ukraine,” according to the State Department.

Even if the U.S. uses the financing authority to purchase weapons, Congress still needs to authorize additional funding to support Ukraine, the U.S. official said.

The administration could also potentially ask Congress to redirect funding from elsewhere in the Pentagon budget to support Ukraine, according to a Defense Department official familiar with the discussions. However, this route would require approval from lawmakers.

A top Pentagon spokesperson said no decision had been made on what route the department will take.

“Reprogramming is always an option for urgent needs. At this time right now, though, to my knowledge, no decision has been made on using reprogramming as a way to support Ukraine security assistance,” said Brig. Gen. Patrick Ryder. “We remain committed to working with Congress on the Ukraine supplemental and receiving a full budget.”

Pentagon leaders warned lawmakers last week that department’s portion of previous aid packages has nearly run out. Comptroller Mike McCord wrote in a letter to congressional leaders that the Defense Department “has exhausted nearly all available security assistance funding for Ukraine.” No money remains for the Ukraine Security Assistance Initiative, the program used by the Pentagon to purchase new weapons and equipment for Kyiv, while $1.6 billion remains to replenish U.S. inventories.

Congress cleared a short-term funding patch to keep the government open last weekend without any new Ukraine money, sidelining Biden’s $24 billion emergency request.

While Biden said he was concerned about the possibility of running out of funding to support Ukraine, he had confidence “a majority of members of the House and Senate, in both parties” support funding the war.

Senate Majority Leader Chuck Schumer said on Wednesday that he and GOP leader Mitch McConnell plan to “work together to get a big package done” for Ukraine. But its fate in the Republican-led House, where a majority of GOP lawmakers last week opposed more money, is less certain.