Prime Minister Alexis Tsipras is participating as an observer in the meeting of the Party of European Socialists in Brussels on Thursday.
The topics discussed are migration, defence, the EU’s external relations, the European digital market and the course of negotiations on Brexit.
Tsipras will then take part in the European Council summit.
Prime Minister had a brief exchange with UK’s Labour leader Jeremy Corbyn during the conference.
“Nice to see you. We’re very proud of what you have accomplished,” Tsipras told Corbyn.
“We are following your example. I believe we will succeed soon,” Corbyn responded.