Pres. Joe Biden marked the first anniversary of Russia's war on Ukraine Mon. with a surprise visit to Kyiv, Ukraine.

Biden arrived in Kyiv early Mon. morning: according to the WaPo, he traveled by overnight train to Kyiv from Poland.

Biden's trip to Kyiv was months in the making, coordinated in secret by Pentagon and White House security officials. (WP)

Biden made the decision to travel to Kyiv on Fri.; he secretly departed Washington DC for Poland at 4 a.m. on Sun.. (WP)

Biden's trip was historic: he is the first president to travel to an active warzone without a US military presence. (ALJ)

Biden and Ukrainian Pres. Volodymyr Zelensky opened the trip Mon. strolling through Kyiv as air raid sirens blared.

Biden and Zelensky also delivered remarks at Mariinsky Palace marking the historic trip.

Biden: "Ukraine stands. Democracy stands. The Americans stand with you."

Biden: "That dark night one year ago, the world was literally at the time bracing for the fall of Kyiv."

Biden: "This is the largest land war in Europe in three quarters of a century, and you’re succeeding against all [odds]."

Biden: "When united, Americans of all political backgrounds decided that they would step up."

Biden: "Together, we’ve committed nearly 700 tanks and thousands of armored vehicles, 1,000 artillery systems..."

Biden: "Putin thought Ukraine was weak and the West was divided."

Biden: "He thought he could outlast us. I don’t think he’s thinking that right now."

Biden: "...one year later, the evidence is right here in this room. We stand here together."