Volodymyr Zelenksy greeted Ursula von der Leyen as she arrived in Kyiv to mark Europe Day on Tuesday 9 May.
A Ukrainian flag was also raised outside the European Commission headquarters in Brussels to celebrate the occasion.
“From now on, 9 May will be Europe Day - in the European Union and also in Ukraine,” Mr Zelensky wrote, sharing a video of himself welcoming the president of the European Commission on Telegram.
“Today, we are meeting in Kyiv on this special day. Because Kyiv is such a fitting place to celebrate the day of Europe.”