Arriving at the meetings with EU presidents, the US president vowed to restore relations with the bloc, saying "America is back".
Joe Biden met with European Council President Charles Michel and European Commission President Ursula von der Leyen in Brussels for the EU-US summit.
The two EU leaders welcomed Biden at the EU Council building.
Speaking ahead of the meetings with European officials, Biden expressed commitment to the bloc.
"America is back. We are committed -- we have never fully left -- but we are reasserting the fact it is overwhelmingly in the interest of the United States to have a great relationship with NATO and with the EU."
"I have a very different view than my predecessor," added Biden, referring to former US President Donald Trump.
Michel, for his part, welcomed Biden's remarks, saying: "You are back in Brussels and America is back on the global scene. It's great news for alliance and it's also good news for the world. We are really delighted to work with you in order to tackle together some important global challenges."
Von der Leyen also welcomed the US president's remarks and described his attendance to the meeting as an "honor."
"Indeed, the last four years have not been easy," she added.
"The world has dramatically changed, Europe has changed, but we want to reassure you, your friends and allies. And we look very much forward to working together," von der Leyen said.