The chairman of the House intelligence committee said he believes the US will ultimately approve a key budget request for Ukraine.
Mike Turner, a Republican, said on Sunday that when the Congress returns from a two-week holiday it may move ahead with approving $60 billion in Ukraine funding.
“I do think that there is an opportunity when we get back to Washington to move this important aid package forward, because it is so critical,” Mr Turner told NBC News.
He said Russian President Vladimir Putin's "atrocities and war crimes in Ukraine" must be responded to.
House Speaker Mike Johnson has thus far refused to put the Senate-approved bill to a vote in the lower chamber because he said it does not include any provisions to strengthen security along the US-Mexico border.
The bill also includes billions of dollars for Israel and Taiwan.
Mr Johnson's excuse is widely viewed as disingenuous because he also barred an earlier bill that included border funding.
Observers say he has not brought it for a vote is because of Donald Trump. The former president has praised Mr Putin and is wary of handing Democrats a legislative win before the November election.
He has told Mr Johnson not to bring the matter for a vote.
But Mr Turner said Mr Johnson has committed to “finding a pathway for the aid for Ukraine".
“I believe him, I think that we will. This does need to get done,” he said.
President Joe Biden blamed US legislators’ failure to approve emergency aid to Ukraine for the fall of Avdiivka, which handed Russia a significant battlefield victory after months of fighting for control of the city.
Mr Biden said he called Ukrainian President Volodymyr Zelenskyy on Saturday “to let him know I’m confident we’re going to get that money", while warning that more Ukrainian cities might fall if Congress does not approve the funding.
Mr Turner said “there’s certainly sufficient support” in the Senate and the House of Representatives to pass the aid package, which has drawn most of the opposition from his party’s right.
“There’s so much on the line,” Mr Biden told reporters near his home in Rehoboth Beach, Delaware.
“The idea that now we’re running out of ammunition – to walk away, I find it absurd. I find it unethical. So I’m going to fight to get them the ammunition they need.”
Ukraine was forced to withdraw from Avdiivka after its “soldiers had to ration ammunition due to dwindling supplies as a result of congressional inaction, resulting in Russia’s first notable gains in months", the White House said in a statement after Mr Biden’s call to Mr Zelenskyy.
Mr Turner caused a stir last week by warning of the threat of a Russian anti-satellite weapon, which the White House later described as posing no current threat.
He brushed off accusations – including by the Kremlin – that his purpose was to drum up support for Ukraine aid, telling NBC that “this is about Russia and the administration taking action".
