The African Union on Wednesday threw its weight behind Italian and U.S.-led moves to stabilize Libya that include arming a national unity government to fight Islamic State militants.

Western powers are also keen to see Prime Minister Fayez al-Sarraj's fledgling administration establish its authority over the whole country so it can actively contribute to efforts to stem the flow of mostly African migrants using Libya as a launchpad to get to Europe.

An Italian prosecutor on Tuesday requested an 18-year prison term for the alleged captain of a migrant boat which sank off Libya in April 2015, killing as many as 800 people, Italian media reported.

The accused skipper, Mohammed Ali Malek, claims he was a migrant himself and had been made to steer the boat by the real traffickers.

Libya's unity government called Tuesday for warplanes and helicopters to fight jihadists as it hailed international support for granting it an exemption to a longstanding embargo on weapons sales.

On Monday, the United States, Italy and Libya's allies and neighbors agreed in Vienna to arm the U.N.-backed Government of National Accord (GNA) to confront the threat from the Islamic State (IS) jihadist group.

The U.S. government is ready to loosen a ban on arms exports to Libya, in a bid to help the country's fledgling unity government fight the Islamic State group, officials and diplomats told AFP Thursday.

Under White House-backed plans, the United Nations would carve out exemptions to an embargo introduced by the Security Council in 2011, during Moammar Gadhafi's failed attempt to suppress a popular uprising.

The head of Libya's unity government has announced plans for a concerted campaign to drive the Islamic State group out of the North African country, but without foreign intervention.

In remarks marking almost 30 days since his arrival in Tripoli to assert the authority of the U.N.-backed Government of National Accord (GNA), Fayez al-Sarraj also appealed for a united Libya.

A Serbian employee of a German company who was kidnapped at the weekend in a remote part of Libya was released Wednesday, the foreign ministry in Belgrade said.

"Miroslav Tomic, 46, employed by German firm Ferrostaal and kidnapped on Sunday afternoon... was freed today," a ministry statement said citing the Serbian embassy in Tripoli, without giving details about the kidnappers.

A Serbian worker has been kidnapped in Libya, Belgrade's foreign ministry said Tuesday, two months after the deaths of two abducted Serbian embassy employees in the North African country.

State broadcaster RTS named the man as 46-year-old Miroslav Tomic, an employee of a German company, who was seized on Saturday while visiting an oil well in a remote area of the lawless country near the border with Egypt.

NATO is ten weeks away from launching a naval mission off Libya as part of a controversial U.S.-backed plan to close the Western Mediterranean migrant route to Europe, officials said Monday.

The advanced state of preparations for the operation was revealed by Italian Defense Minister Roberta Pinotti as leaders of the U.S., Britain, France, Germany and Italy met in Germany.

Libya's Vice President Ahmed Maetig has expressed hope that the European Union will enter into an agreement with his country similar to that between the EU and Turkey restricting the flow of migrants to Europe.

Maetig made the appeal while in Rome meeting with Italy's Interior Minister Angelino Alfano.

At least eight African migrants, and possibly as many as 27, died in a new boat tragedy off the coast of Libya, a search and rescue organization said Monday.

French charity SOS Mediterranee said its boat, the Aquarius, had rescued 108 migrants from a stricken dinghy in high seas on Sunday.