President Joe Biden, in a call Saturday with Ukrainian President Volodymyr Zelensky, 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.

“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.