The Arab League is set to hold an emergency meeting Tuesday at the request of Libya's internationally recognized government, which is under attack by Islamic State militants.
The Tobruk-based government asked for help from regional allies late Saturday, including airstrikes.
The request follows dozens of deaths last week in the coastal city of Sirte, where a group that included local residents attacked Islamic State fighters.
The militants took over the city in June and have declared a presence in at least three areas around the country and publicized several mass executions, taking advantage of an already tumultuous internal conflict in Libya.
Several Middle Eastern governments are participating in the U.S.-led air offensive against Islamic State fighters in Syria and Iraq. Only Egypt and the United Arab Emirate have briefly taken aim at the militant group in Libya.
International support sought
Earlier this year, Libyan Foreign Minister Mohammed al-Dairi asked for international support for the Libyan National Army to counter "terrorism," including the Islamic State group.
On Saturday, the U.N.'s mission to the country called it "high time that Libyans set aside their differences and join together to confront the scourge of Daesh (Islamic State)," referring to another name for the Islamic State group.
The presence of Islamic State fighters adds to what was already a country stricken by internal violence, with rival militias and two governments – one in Tobruk, another in Tripoli – vying for control.
Efforts to rebuild the state following the overthrow and death of longtime leader Moammar Gadhafi nearly four years ago in Sirte have not lasted, despite repeated U.N. attempts to broker a peace deal.