The push for another lethal aid package comes as lawmakers and the Biden administration alike are looking to redouble U.S. support for Ukraine as the country’s war with Russia enters a new phase in the Donbas region. The president will formally request the money next week when lawmakers return to Washington.

“I support a package to address continued research and investment and therapeutics and vaccinations that we need for Covid … but I also think it’s very important to get this aid out to Ukraine as quickly as possible,” Sen. Jeanne Shaheen (D-N.H.) told reporters on a conference call from the Balkans, where she traveled this week alongside Sens. Chris Murphy (D-Conn.) and Thom Tillis (R-N.C.).

Murphy said he was “open to any pathway that is the fastest” to get both Ukraine aid and Covid assistance to the president’s desk. Tillis, on the other hand, said that while he supports new funding for Covid therapeutics, it shouldn’t slow down the Ukraine portion.

“If that [Covid aid] discussion is going to take a matter of weeks, we have to make a decision on Ukrainian support in a matter of hours or days,” Tillis said.

The urgency for new aid follows several lawmaker visits to the region over the two-week congressional recess. Last week, Sen. Steve Daines (R-Mont.) and Ukraine-born Rep. Victoria Spartz (R-Ind.) were the first American officials known to have traveled to Ukraine since Russia’s invasion began in February.

Biden announced an additional $800 million in military aid for Ukraine on Thursday, and in doing so revealed that he has “almost exhausted” a key fund that Congress created as part of the last Ukraine package. He said he would be asking Congress for additional funding next week “in order to sustain Ukraine for the duration of this fight” and “keep weapons and ammunition flowing without interruption.”The president said he wants Congress to move “quickly” on the request, but it could get slowed down if lawmakers try to tack on other White House priorities. And amid the criticism over Title 42, Democrats have discussed potentially crafting a supplemental appropriations bill for the border.

Covid aid was put on hold before the current congressional recess after Republicans sought to halt Biden’s decision to scrap Title 42. Since then, pressure on Biden has only grown — including from within his own party. Granting amendment votes on Title 42 would be tricky for Democratic Senate leaders, since there’s a possibility enough Democrats would side with Republicans.

Still, Congress’ top priority remains providing additional military and humanitarian assistance for Ukraine and ensuring that the aid is delivered promptly, with as few bureaucratic hurdles as possible. Speaker Nancy Pelosi said Thursday she plans to take up aid “as soon as we can next week,” though her spokesperson, Drew Hammill, later clarified that there is “no specific timeline for a floor vote at this time.”

Before the recess, the Senate unanimously approved a bill to reestablish a World War II-era program known as Lend-Lease, which would allow the U.S. to more efficiently send weapons and other critical supplies to Ukraine with the promise of repayment at a later date.

House leaders are in discussions about putting that legislation on the floor next week, and sending it to Biden’s desk. It would be put up for a vote under a procedure that requires support from two-thirds of the chamber for passage.

Lawmakers are also exploring additional avenues for humanitarian assistance to help rebuild Ukrainian cities and towns pummeled by Russian shelling. And they’re eyeing Biden’s forthcoming request for military assistance as a possible catch-all vehicle for related measures.