Carmelo Imbesi, Associated Press
In this Tuesday, May 13, 2014 file photo, the Italian Navy frigate "Grecale", carrying victims and survivors of a migrant boat which sank in the Mediterranean Sea, arrives at the Catania harbor, Sicily, Italy, Tuesday, May 13, 2014.

ROME — Italy insisted Friday that lives won't be sacrificed as it ended its costly Mediterranean Sea rescue operation and shifted over to a less ambitious joint patrol with the European Union.

Italy launched the Mare Nostrum (Our Sea) operation last year after 366 would-be migrants drowned off Sicily. Italian ships and aircraft involved in the 9.5 million-euro ($11.9 million) per month mission patrolled close to the Libyan coast, rescuing over 100,000 people who had paid smugglers to bring them to Europe.

Italy had long insisted that Europe must do more to shoulder the burden of rescuing migrants. Rome successfully lobbied to have the EU's Frontex border control agency launch a new operation, Tritone, which begins Saturday.

Some 21 EU nations have said they would be willing to contribute ships, aircraft and personnel to the Tritone mission, which has a budget of 2.9 million euros ($3.6 million) a month, the European Commission said.

While Alfano hailed the end of the politically unpopular rescue program, Italy will still be spending about 3.5 million euros ($4.4 million) a month to keep a third of its sea fleet on hand for rescue missions alongside Frontex for the next two months. He also said Italy would still honor its obligations to respond to ships in distress.

But he acknowledged that while Mare Nostrum "almost reached the North African coast," Frontex will be patrolling Europe's borders, not Libya's.

Critics of Mare Nostrum had argued that patrolling so close to Libya encouraged migrants to take the risky trip out to sea.

The EU says Frontex is not replacing Italy's obligation to rescue ships in distress, terming the Tritone operation as one "in support of" Italian efforts.

Associated Press writer John-Thor Dahlburg in Brussels contributed. Follow Nicole Winfield at