Angela Merkel and Francois Hollande will join Italy's PM Matteo Renzi on an island off the coast of Naples ahead of September's EU summit to discuss the consequences of Brexit vote and how to shape the future of Europe.
"They will be coming to discuss how to relaunch Europe from the bottom up, there's a big need," Prime Minister Renzi said on Sunday.
"The goal must first of all be to preserve the status quo and to prevent a further disintegration of the EU-27," according to one EU diplomat.
The EU is currently facing risk of another referendum in Netherlands, which may be well followed by other countries.
Germany also opposes any attempts to confront existing deficit and debt constraints, but France and Italy, who have troubles achieving the specified figures, call for expansionary measures and reduced economic austerity.
Others topics for discussion will be EU's current policy on migrants, which is reportedly already opposed by Hungary's PM Viktor Orban, who is going to call for a referendum on whether to accept any future EU migrant settlement quotas.
The leaders will also discuss the naval operation in the Mediterranean, aimed at tackling the migrant smugglers, help enforce an arms embargo off Libya, and train the Libyan coast guard.