UN Secretary General Ban Ki-moon, Italian Prime Minister Matteo Renzi and EU foreign policy chief Federica Mogherini will on Monday board a vessel in the Mediterranean Sea to show their "solidarity" after a series of boat migrant tragedies, the EU said.

The trio will set sail on an Italian navy ship off the coast of Sicily "to assess the situation and help ensure European solidarity for the efforts undertaken to save the lives of migrants crossing the Mediterranean Sea", the EU's diplomatic arm said in a statement Saturday.