A rescue vessel carrying 629 migrants is stranded in the Mediterranean after Italy’s new interior minister refused permission for it to dock.
Matteo Salvini, leader of the right-wing League, said Malta should accept the Aquarius but he was rejected.
Malta says the German charity SOS Méditerranée picked up the migrants in Libyan waters, which means they fall under Italy’s jurisdiction.
Italy is the main entry for migrants crossing from North Africa to Europe.
The League promised voters during Italy’s recent general election that it would take a tough stance on immigration.