The US is considering a new campaign of military action in Libya against Isis, the Pentagon said on Wednesday, amid worries that the jihadist group could seize control of a larger slice of territory in the country. Peter Cook, Pentagon press secretary, said the US was “looking at military options” for Libya “in the event” that Isis “becomes more of a threat than it is even today”. Officials said the potential options would include concerted air strikes against Isis and limited operations by special operations forces. The plans for potential military action in Libya come four years after the civil war and subsequent western campaign to topple Muammer Gaddafi. The chaos and instability in the country since then has created space for Isis and other militant groups to prosper. Alarm in western capitals about Libya has grown in recent weeks as Isis, which already controls a long strip of coastline around the city of Sirte, has used heavy weapons to launch attacks against a series of oil facilities. US officials say there has been an influx of Isis fighters into Libya, partly as a result of the stronger controls on the flow of fighters into Syria from Turkey. However, there is also concern among western officials that a new outside military intervention against Isis could hamper the political process aimed at forging a new national unity government in Libya.