Italy's far-right interior minister on Sunday threatened to return to Libya 177 migrants who have been stuck on an Italian coast guard ship for days amid an ongoing standoff with Malta over their fate.
Interior Minister Matteo Salvini demanded the European Union step in after Malta refused to let the Diciotti ship dock at its port.
"Either Europe decides to seriously offer Italy some concrete help, beginning with, for example, the 180 immigrants on board the Diciotti ship, or we will be forced to do what will definitively stop the smugglers' business. That means taking the people saved in the sea back to Libya," Salvini said in a statement.
The Diciotti, working under the EU's Frontex Mediterranean rescue operation, has been stuck off the coast of the Italian island of Lampedusa after rescuing the migrants on August 16.
Italy asked Malta to take in the migrants, arguing that they were rescued in Maltese waters. But Malta refused, saying that the migrant boat wasn't in distress and that the migrants declined help from Maltese authorities, preferring to continue toward Italy.
Salvini's Maltese counterpart, Michael Farrugia, tweeted on Sunday, accusing Italy of rescuing the migrants in Maltese waters "purely to prevent them from entering Italian waters."
Italy's transport minister, Danilo Toninelli, said Malta's position was "worthy of sanction" and called on EU countries to open their ports.
The spat between Italy and Malta is the second in just over a month. The two governments were locked in a standoff over 450 migrants rescued from a fishing ship. The migrants were taken aboard two EU border agency vessels, which were eventually allowed to dock in Italy after five European countries agreed to take 50 each.
Returning migrants to an "unsafe" Libya could pose legal troubles for Rome.
International law states that migrants rescued in international waters cannot be returned to a place where their lives are put in danger. Libya is classified as unsafe by both the United Nations and the European Union.
The UN refugee agency is looking into possible violations of international law by an Italian-flagged mercantile ship, which rescued more than 100 migrants and returned them to Libya in July.
Rome was faulted by the European Court of Human Rights in 2012 for using its own ships to return migrants to Libya.