U.S. President Joe Biden said “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.” Biden called on lawmakers to approve $60 billion in aid to Ukraine that has been held up in the U.S. Congress.

The fall of Avdiivka is Russia’s biggest gain since capturing the city of Bakhmut in May 2023, and comes almost two years to the day since Russian President Vladimir Putin launched his full-scale invasion of Ukraine.

Ukraine’s newly appointed military chief, Gen. Oleksandr Syrsky, said in a statement that he decided to withdraw forces from the embattled city to “avoid encirclement [by Russian troops] and preserve the lives and health of servicemen.”

Moscow said that some Ukrainian troops were still holed up in an industrial plant in the Avdiivka area, according to media reports. Russian Defense Minister Sergei Shoigu told the Kremlin that Russian forces were working to clear final pockets of resistance at the Avdiivka Coke and Chemical Plant, officials said in a statement.

Outnumbered Ukrainian defenders had battled a Russian assault around Avdiivka for four months in one of the most intense battles of the war. Zelenskyy said Russian forces had been suffering seven casualties for every Ukrainian death in Avdiivka, but even that death rate wasn’t stopping the attacks.

“Russia has only one specific advantage, complete devaluation of human life,” Zelenskyy said.