Republican Senators in the US have blocked a move to pass an aid bill for Ukraine after failing to secure border compromises they sought in exchange.
The $110bn package included $61bn for Ukraine, as well as funds for Israel and aid for Gaza.
Republicans are insisting that any aid to Ukraine be tied to sweeping US immigration and asylum reforms.
The White House has warned that US funds for Ukraine could soon run out.
Senators voted 51 to 49 against advancing the bill, with 60 votes needed. The vote throws uncertainty into the future of aid for Ukraine and sends lawmakers back to the negotiating table with just days to go until Congress has scheduled winter break.
Every single Republican Senator voted against the measure, along with independent Senator Bernie Sanders, who had earlier in the day expressed reservations that the legislation included billions in military aid for Israel.
“I do not believe we should be appropriating over $10 billion for the right-wing extremist Netanyahu government to continue its current military approach,” Mr Sanders said, referring to Israeli Prime Minister Benjamin Netanyahu’s ongoing campaign in the Gaza strip, which has so far killed thousands of civilians.
Mr Sanders, who is a long-time critic of Mr Netanyahu, added: “What the Netanyahu government is doing is immoral, it is in violation of international law, and the United States should not be complicit in those actions.”
Earlier on Wednesday, US President Joe Biden said he was “willing to make significant compromises on the border” in order to get the aid bill passed.
“This cannot wait,” he said, adding that “Republicans in Congress are willing to give Putin the greatest gift he could hope for”.
Concerns over the future of the $110bn package grew on Tuesday after a classified briefing for lawmakers aimed at shoring up support for new funds broke down spectacularly.
The package already includes provisions for border security, but Republican demands for additional changes to asylum rules has complicated negotiations with Democrats.
While the party’s members are overwhelmingly in favour of aid to Ukraine, some have sought to use the issue as a way address mounting domestic concerns over the US southern border.
Since Russia invaded Ukraine in February 2022, Congress has approved over $110bn in military and economic aid to Ukraine, most of which has already been distributed.
