European Union militaries were ordered to step up surveillance in the south-central Mediterranean Sea in preparation for possible combat against human-trafficking gangs operating out of Libya.

In a prelude to the bloc’s riskiest military venture ever, EU foreign ministers meeting in Luxembourg approved the dispatch of five warships, two submarines, three reconnaissance planes, three helicopters and two drones to monitor smugglers and help with rescues at sea.

"The targets are not the migrants, the targets are those that are making money on their lives and too often on their deaths," EU foreign policy chief Federica Mogherini told reporters on Monday.

Moving to actual combat to address the Mediterranean migration crisis hinges on approval by the United Nations Security Council and the establishment of a unity government in strife-ridden Libya.

Syria’s civil war, Libya’s disintegration and turmoil in northern Africa have pushed migration to Europe to levels not seen since the early 1990s, with 185,000 refugees gaining asylum in the 28-nation bloc in 2014.

EU governments remains at odds over what to do with refugees who reach European shores, with most countries opposing proposed national quotas for sheltering them and weighing their cases for political asylum.

Twelve countries will take part in the military mission, headquartered in Rome under the command of Italian Rear Admiral Enrico Credendino. The Italian aircraft carrier Cavour will serve as the sea-based command center and as a hospital ship to treat injured and sick refugees.

The intelligence-gathering phase will start in early July and reach full strength in late July, ultimately involving 1,000 troops. It will track smuggling networks to feed into planning for possible future combat.