He also stopped by the U.S. Embassy and thanked the staff there, saying "thanks for taking care of each other and thanks for being such great professionals."

"I'm here today to deliver an important message - the United States will continue to stand with Ukraine in their fight for freedom against Russia's aggression, both now and into the future," Austin said on social media platform X. Zelenskiy also sent birthday wishes to Biden who turned 81 on Monday.