Italy has now overtaken Greece as the main point of entry for migrants trying to reach Europe, figures from the UN refugee agency (UNHCR) show.
More than 144,000 migrants have reached Italy so far this year, compared to the nearly 154,000 arrivals in the whole of 2015. Arrivals to Greece fell sharply after the EU struck a deal with Turkey to prevent departures from its shores.
"In terms of irregular migration right now Italy is the member state number one," Fabrice Leggeri, head of the European Border and Coast Guard, told reporters.
"We have to be vigilant in the central Mediterranean area because there may also be security risks there, not just the migratory pressure," Leggeri said.
Some 90% of arrivals in Italy began their voyage on smugglers' boats in Libya, though there has been an increase in migrants arriving from Egypt in recent weeks, EU officials say.
But nearly all those who reach the Italian coast arrive on EU rescue vessels, having been plucked from the sea or saved from overcrowded, unsafe dinghies, according to officials.