President Joe Biden, in a call with Ukrainian President Volodymyr Zelenskyy, directly tied Ukraine’s withdrawal from the key town of Avdiivka to Congress’ inability to pass further aid for the country’s effort to fend off Russia’s invasion, Report informs via CNN.

“This morning, Ukraine’s military was forced to withdraw from Avdiivka after Ukrainian soldiers had to ration ammunition due to dwindling supplies as a result of congressional inaction, resulting in Russia’s first notable gains in months. President Biden emphasized the need for Congress to urgently pass the national security supplemental funding bill to resupply Ukrainian forces,” according to a White House readout of the call.

The call bookended a week defined by US attempts to reassert leadership on the world stage. It also highlighted renewed urgency to pass additional funds for Ukraine amid the withdrawal from Avdiivka, a key town that in recent months became one of the most fiercely contested battles on the eastern front, and the news of Kremlin critic Alexey Navalny’s death.

Biden told reporters later Saturday that he’s not confident other Ukrainian towns wouldn’t also fall, adding it is “unethical” that the US is not providing more aid to the Ukrainian people after they have fought “so bravely and heroically.”

“The idea that now they are running out of ammunition, and we walk away. I find it absurd. I find it unethical,” Biden said in Rehoboth Beach, Delaware. “I find it contrary to everything we are as a country.”

Earlier this week, the Senate passed with bipartisan support a $95.3 billion foreign aid bill, which includes $60 billion to support Ukraine. However, GOP House Speaker Mike Johnson has said he does not plan to bring the bill to the floor, and the House is on a two-week break.

US officials have recently expressed concern about Russian gains in the war, suggesting it’s a reflection of a slowdown in aid. National Security Council spokesperson Adrienne Watson also said in a statement shared with CNN that the withdrawal from Avdiivka is a direct result of the foreign aid bill being stalled in Congress.

“This is the cost of Congressional inaction. The Ukrainians continue to fight bravely, but they are running low on supplies. It is critical that the House approve additional Ukraine funding without delay so that we can provide Ukraine with the artillery ammunition and other critical equipment they need to defend their country,” she said.

Biden’s call followed similar ones earlier Saturday from Vice President Kamala Harris and Zelenskyy urging Congress to pass additional aid for Ukraine, with Harris slamming House Republicans for stalling legislation.

“Political gamesmanship has no role to play in what is fundamentally about the significance of standing with an ally as it endures an unprovoked aggression,” Harris told reporters following a bilateral meeting with Zelenskyy at the Munich Security Conference in Germany.

She said she has “full belief that were the supplemental package and security package to make it to the floor of the House of Representatives, that it would actually pass.”

“For us, this package is vital,” Zelensky said, according to a translation. “We do not currently look into alternatives because we are counting on the United States.”

While the Ukrainian leader said he does not consider the lack of additional funding a betrayal, he hinted at the House being on recess until the end of the month.

“Please, everyone, remember that dictators do not go on vacation,” he said during a speech at the conference. “Hatred knows no pause. Enemy artillery does not fall silent due to procedural issues.”

Biden on Friday criticized House lawmakers for taking a two-week break, calling it “outrageous” and telling reporters it’s “about time they step up” following the death of Russian opposition figure Navalny.

“Two weeks, they’re walking away,” Biden said at the White House. “Two weeks. What are they thinking? My God, this is bizarre, and it’s just reinforcing all of the concern and almost – I won’t say panic – but real concern about the United States being a reliable ally. This is outrageous.”