U.S. President Joe Biden made a surprise visit to Kyiv on Monday ahead of the first anniversary of the invasion of Ukraine.

“As the world prepares to mark the one-year anniversary of Russia’s brutal invasion of Ukraine, I am in Kyiv today to meet with President Zelenskyy and reaffirm our unwavering and unflagging commitment to Ukraine’s democracy, sovereignty, and territorial integrity,” said the U.S. President in a statement released by the White House.

Ukrainian President Volodymyr Zelenskyy noted this was the first visit of the U.S. President to Ukraine in almost 15 years and the most important visit in the history of Ukrainian-American relations.

“Right now, the fate of the rules-based international order is being decided in Ukraine. Together with Mr. President Biden, our allies and partners, we must continue to do everything possible to ensure that the democratic world wins this historic battle,” he added.

Biden also announced the delivery of critical equipment, including artillery ammunition, anti-armor systems, and air surveillance radars.