WASHINGTON — President Joe Biden blamed U.S. lawmakers’ 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.

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 doesn’t approve the funding.

“There’s so much on the line,” 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.”

Attempts to unlock emergency foreign aid to U.S. allies have been stuck in a partisan deadlock in Congress for months, leaving Biden and Zelenskyy to make increasingly urgent appeals for Congress to move forward as Ukrainian supplies run low.

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 Biden’s call to Zelenskyy.

The U.S. Senate this week approved $95 billion in assistance for Ukraine, Israel and Taiwan after months of delay, but the legislation still faces formidable obstacles in the Republican-led House of Representatives.

Biden “emphasized the need for Congress to urgently pass the national security supplemental funding bill to resupply Ukrainian forces,” according to the call readout.

Rep. Mike Turner, an Ohio Republican who heads the House’s intelligence committee, said “there’s certainly sufficient support” in both houses to pass the aid package, which has drawn the most opposition on his party’s right flank.

Opposition activist Alexei Navalny’s death in a Russian prison camp means “that we should even be that more strong in funding Ukraine and passing this in the House and Senate,” to honor his legacy, Turner said in an interview with NBC’s Meet the Press for broadcast Sunday.

Turner caused a stir this 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.”

‘Artificial’ shortage

Ukraine’s military said earlier Saturday it’s withdrawing from Avdiivka, the same day that Zelenskyy addressed an annual conference of military and foreign-policy leaders in Munich. He told the meeting that Ukraine was withdrawing to save lives.

Zelenskyy renewed appeals for allies to arm Ukraine, saying Russian President Vladimir Putin is reaping the advantage.

“Keeping Ukraine in an artificial deficit of artillery and long-range weapons allows Putin to adapt to the current intensity of the war,” he told the Munich Security Conference, where he met Saturday with Vice President Kamala Harris.

Ukraine is struggling with dwindling military supplies as Russian forces press their offensive at a time of uncertainty about U.S. aid. Zelenskyy changed his military leadership last week as Russia’s full-scale invasion heads toward a third year.

Avdiivka, an industrial satellite city located just north of Donetsk — a regional capital under de-facto Kremlin control since 2014 — has been battered by bombardment and heavy fighting since spring 2022.

Losing the city, once home to 30,000 people, adds to problems for Ukraine’s political and military leadership, which is also struggling with a lack of soldiers and war fatigue.

The Kremlin made Avdiivka a priority in a year when neither side is expected to make major strategic gains on the battlefield, according to Western officials who spoke on condition of anonymity. Large swaths of territory last changed hands in Ukraine more than a year ago, when Kyiv’s troops liberated part of the Kherson region.

European officials, who recently approved a more than $50 billion aid package for Ukraine, have been increasingly concerned by the delays in Washington.