The six leaders met for an informal dinner. Prime Ministers Andrej Plenkovic of Croatia and Krisjanis Karins of Latvia negotiated on behalf of the European People's Party, Dutch PM Mark Rutte and Belgian PM Charles Michel represented the Liberals, and Spanish PM Pedro Sanchez and Portuguese PM Antonio Costa represented the Socialists.
The meeting was constructive and common challenges were identified, per the press release. Participants agreed to meet again in the next few days.
This informal process does not replace official debates in the European Council and Parliament, the press release added.
At an EU28 summit on May 28, two days after European elections, it was agreed that European Council President Donald Tusk should begin consultations with the heads of state or government on the news appointments to top jobs.
Negotiations between the pro-European groups in the European Parliament - the EPP, the Social Democrats, the Liberals, and the Greens - will begin on June 12. They will first attempt to agree on a coalition programme and then on a presidential candidate for the European Commission.
The three largest groups in the European Parliament - the EPP, the Social Democrats, and the Liberals - have each appointed two representatives, members of the European Council, to help Tusk, the six leaders who met in Brussels on Friday.
The Brussels meeting was the first between the six leaders. It was convened by the Belgian prime minister.
Talks will continue in European institutions in the days and weeks ahead to nominate a Commission president who can get the support of the European Council, which meets on June 20-21, and the European Parliament.
The appointment of a new Commission president is to be followed by the appointment of the presidents of the European Parliament, the European Council and the European Central Bank as well as the high representative for the common foreign and security policy.