"During the meeting, the sides discussed cooperation between Azerbaijan and the European Union in the field of energy," the Azeri presidency said.
On the green energy, the two agreed that this area of cooperation had "great prospects."
Aliyev, who came to Belgium ahead of three-corner talks with Armenian Prime Minister Nikol Pashinyan and EU chief Charles Michel on Sunday, said he was pleased to see Azeri gas supplies "covering a wider geography in the European area."
The European Union turned to the South Caucasus nation after vowing last year to ditch Russian gas in response to Russia's special military operation in Ukraine. Top EU officials have been touring Asia and northern Africa in search of alternative sources as high energy prices battered Europe.
European Commission President Ursula von Der Leyen traveled to Azerbaijan in July to secure a strategic energy partnership deal with Baku, which is bidding on the Southern Gas Corridor link between the Caspian region and Europe to bring more Azeri gas to the lucrative European market.