The warning was issued by White House budget director Shalanda Young on Monday, Polish state news agency PAP reported.
In a letter to the House of Representatives, Young stated that, without action by lawmakers, the White House "will run out of resources to procure more weapons and equipment for Ukraine" by the end of the year.
She warned that "cutting off the flow" of US arms and hardware would "put at risk" Ukraine's battlefield gains and raise "the likelihood of Russian military victories."
In October, Biden asked Congress for a USD 106 billion national security package, including USD 61 billion in military assistance for Ukraine, the AFP news agency reported.
The proposal has stalled on Capitol Hill amid growing opposition within the Republican Party to further assistance for Kyiv, the PAP news agency reported.
US National Security Advisor Jake Sullivan said on Monday that US lawmakers faced a choice between continued support for Ukraine or letting Russian President Vladimir Putin prevail.
Sullivan told reporters: "It is that stark choice, and we hope that Congress on a bipartisan basis will make the right choice.”
Russia invaded Ukraine on February 24, 2022, launching the largest military campaign in Europe since World War II.
Tuesday is day 650 of Russia’s war on Ukraine.
Source: IAR, PAP, AFP, CNN, France24