European Commission President Ursula von der Leyen arrived in Kyiv in the early hours of May 9.
"Good to be back in Kyiv," she tweeted. "Where the values we hold dear are defended everyday. So it is such a fitting place to celebrate the day of Europe."
The Commission's press service reported earlier that she will reaffirm the EU's unwavering support for Ukraine on Europe Day.
On May 8, Zelensky signed a decree on celebrating Europe Day in Ukraine. It is held annually in the EU member countries to celebrate "peace and unity in Europe."
This day marks the anniversary of the Schuman Declaration signing in 1950, which "was an ambitious plan to secure long-term peace in post-war Europe that is considered the beginning of what is now the European Union."
Ukraine officially applied for EU membership in late February 2022, just days after Russia launched its full-scale invasion, and was granted candidacy status in June 2022. On Feb. 11, President Volodymyr Zelensky said that Ukraine wants to become a member of the EU in two years and a member of NATO following its victory against Russia.