(Bloomberg) -- New US aid for Ukraine risks slipping to mid-December and maybe longer, casting doubt on Washington’s ability to keep up the flow of weapons that both the Biden administration and the Ukrainian government say is vital.

Ukraine’s congressional backers are engaged in a tough battle over an expansive aid package whose fate is now enmeshed in a partisan fight over border policies and torn from must-pass bills that would prompt swift action. 

The soonest Congress could complete negotiations and pass new Ukraine assistance is mid-December, nearly two months after President Joe Biden first requested $61 billion for the country in its war against Russia. 

The US has begun restricting the flow of military assistance because of the wait, according to a Defense Department spokeswoman.

Senators in both parties plan to work on a deal in the coming days on an aid package, coupled with border policies, that they can vote on after returning to Washington from the Thanksgiving holiday later this month. 

“We need to push ourselves to negotiate over the next week,” Chris Coons, a Delaware Democrat with close ties to Biden, said on Thursday. 

“The Ukrainians are running out of fuel, weapons and ammunition,” Coons added. Congress must act “on a timeline that’s going to matter.”

With the battlefield settling into a stalemate as the conflict drags toward its third year, once-broad support for Ukraine is showing cracks as the Kremlin bets that it can outlast Kyiv’s backers in the US and Europe. 

Republican infighting and hardliner demands threaten to push congressional consideration of the latest tranche of ammunition and weaponry into the new year despite warnings from White House National Security spokesman John Kirby that the US is “near the end of the road” in resources available for Ukraine.

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“It’s an active battlefront and our ability to continue to support Ukraine is increasingly at jeopardy,” Kirby said.

Influential congressional supporters of Ukraine said they remain confident of more US assistance. House Foreign Affairs Chairman Michael McCaul said there is “no chance” the aid won’t be approved. “It’s just too important.”

But that will be politically difficult for House Speaker Mike Johnson, who is managing a backlash among hardline conservatives over his plan to avert a US government shutdown. Many of those ultra-conservatives also oppose Ukraine assistance, and it would only take a few of them to overthrow Johnson, just as they did his predecessor, Kevin McCarthy.

Representative Chip Roy, a Texas Republican in the hardline Freedom Caucus, warned of “trouble in so-called paradise” if Republican leaders allow a vote on Ukraine aid without meeting ultra-conservatives’ demands on immigration policy changes.

Action Ahead

In the Senate, Majority Leader Chuck Schumer has promised Democrats like Coons that a Ukraine bill would be put up for a vote after Thanksgiving recess. Schumer has also acknowledged that any Ukraine package would include a border policy deal. 

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Top Senate spending panel Republican Susan Collins late Wednesday said closed-door border policy talks were improving and aiming for a deal next week. 

“I’m told that, whereas over the weekend it looked very bleak, that there are new signs of life, today,” she said.

Some Republicans see an opportunity for an immigration deal — something that has eluded Congress for a generation — with the migrant crisis, which effects many Democratic cities.

Still, Johnson may have to compromise on some conservative border policy demands, such as greatly curtailing the right to seek asylum in the US, to get a Ukraine aid deal. And that could provoke conservatives who have so far granted him a honeymoon period. 

The mere promise of legislation won’t placate Johnson’s restive right flank, which now wants to tie distribution of Ukraine aid dollars to achieving specific targets in bringing down border crossings. That would leave the timeline for weaponry uncertain, even after congressional approval. 

These hard demands are so far from what Democrats can accept, it has raised concerns in that party that no Senate deal can be struck that the House will accept. The consequences on the battlefront would be profound.

“If we do not provide additional assistance to Ukraine before the end of the year, it would be a mistake of historic proportions,” said Senate Intelligence Chairman Mark Warner.

--With assistance from Allyson Versprille, Maeve Sheehey and Steven T. Dennis.

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