Regional foreign ministers will meet for the talks, according to Italy's Paolo Gentiloni. He did not give details on who would attend, but past talks on Libya have included the Unied States and European officials and Libya's North African neighbours.

Prime Minister Fayez Serraj's U.N-backed Government of National Accord arrived in Tripoli a month ago, but it has faced resistance from hardliners in both the Libyan factions running rival governments.

"There will be a meeting in Vienna on May 16 to support the government of Serraj and to push for stability in Libya," the minister said, according to a Tunisian foreign ministry statement. "Regional foreign ministers and other important figures will be there."

Five years after the fall of Muammar Gaddafi, western powers are backing Serraj's government as the best solution to chaos in Libya. They are waiting for a request from Serraj for military aid to help in the fight against Islamic State in Libya.

Islamic State took advantage of Libya's political turmoil to establish itself in Sirte last year. It controls a strip of coast about 250 km (155 miles) long around the city, but it has struggled to hold ground elsewhere in the country.

Western governments hope the U.N.-backed government will be able to unite Libya's armed factions to take on Islamic State. But efforts to counter the group have so far depended on loose alliances of armed brigades that supported the rival governments operating in Tripoli and the east. (Reporting by Tarek Amara; writing by Patrick Markey)