The European Union's border agency Frontex launched a new Mediterranean operation called Themis on Thursday, removing the obligation of the previous mission to bring rescued migrants only to Italy.

Italy has repeatedly lamented a lack of EU solidarity in managing immigration. The previous Frontex operation, called Triton, required all those rescued at sea to be brought to Italy even if another EU country, such as Malta, was closer.

"Triton said that whomever rescued would be taken to Italy," said Izabella Cooper, a spokeswoman for Frontex. "Themis leaves the decision on disembarkation to the (country) coordinating a particular rescue."