President Biden made a surprise visit to Kyiv, Ukraine early Monday morning in a show of support for the war-torn country. The visit comes on the eve of the one-year anniversary of Russia launching the war.

Ukrainian president Volodymyr Zelensky met with his American counterpart and the two were seen walking through the streets of Kyiv as air-raid sirens blared in the background.

“When Putin launched his invasion nearly one year ago, he thought Ukraine was weak and the West was divided. He thought he could outlast us. But he was dead wrong,” Biden said in a statement after his arrival.

Biden promised a new half-billion dollar package of critical equipment, including artillery ammunition, anti-armor systems, and air surveillance radars. A fresh round of sanctions against Russia will be announced later in the week.