Ukrainian President Volodymyr Zelensky said Saturday that his country’s military will face a “hard battle” as Russian forces withdrawing from around Kyiv are expected to launch a new offensive in eastern Ukraine, Reuters reports.

“Yes, [Russian] forces are gathering in the east [of Ukraine],” Zelensky said during a joint press conference in Kyiv with Austrian Chancellor Karl Nehammer.

“This will be a hard battle. We believe in this fight and our victory. We are ready to simultaneously fight and look for diplomatic ways to put an end to this war,” Zelensky added.

Writing at The Associated Press, Robert Burns called the withdrawal from Kyiv a “Russian defeat for the ages.”

Zelensky’s statement came one day after a Russian missile attack on a train station in eastern Ukraine killed at least 52 civilians who were attempting to flee the region. Zelensky condemned the attack on the train station as “another war crime of Russia, for which everyone involved will be held accountable,” according to The Washington Post.