The statement late yesterday came after the IS affiliate seized control of a new neighborhood in Sirte. The affiliate shelled the area, killed a senior cleric and hung the bodies of prisoners they killed over bridges.
The government also called for an end to the arms embargo imposed since 2011.
The Arab League said today it will hold an emergency meeting on Libya Tuesday.
Egypt, which is lobbying for a more active international role in Libya against IS, has carried out multiple airstrikes inside Libya against IS, including some after the group killed 21 Egyptian hostages held in Libya.