French President Francois Hollande, German Chancellor Angela Merkel and Italian Prime Minister Matteo Renzi were scheduled to meet later on Monday for the meeting, Efe news reported.
The last such meeting came following the British electorate's decision to leave the bloc following a membership referendum on June 23.
The meeting is to foreshadow the September 16th EU summit in Bratislava.
Security measures are set to be high on the agenda in light of the recent terrorist attacks in France and Germany with proposals of deployable European military units or the creation of a European border guards corps is likely to be brought to the discussion table.
It is expected that the leaders will deliberate EU High Representative Federica Mogherini's draft "Global Strategy on Foreign and Security Policy for the European Union."
Renzi is also due to discuss his paper "Migration Compact", which calls for aid programmes in African countries with a large migrant flow to Europe.
