Libya's prime minister called for a national reconciliation initiative to repair the divisions in a fragmented country reeling from the turbulence that has followed the fall of dictator Muammar Gaddafi.

Fayez Seraj also told Reuters in an interview that the battle against Islamic State militants in their former stronghold of Sirte was in its last stages, although bombings and booby traps still posed a challenge.

Gaddafi's fall in 2011 brought chaos that splintered the North African country into rival armed fiefdoms. The U.N.-backed Government of National Accord (GNA) has been seeking endorsement for months as it tries to extend its authority beyond its base in Tripoli, in western Libya.

"In the last five years, Libya has been through a very difficult and critical phase ... many political divisions," Seraj said in New York, where he was attending an annual UN gathering of world leaders. "There was disintegration of the social fabric as a result of bloody conflicts.

"So we need a real reconciliation between Libyans inside and Libyans abroad ... there will be no exclusion of any political faction," he said. "Reconciliation will provide political stability, which will give way for economic stability."

Seraj said he expected to begin the drive before the end of the year but he faces an unenviable task.

General Khalifa Haftar, who has been waging a military campaign against Islamists and other opponents in Benghazi and the east, and his backers in eastern Libya have been in a stand-off with the GNA for months. They have blocked a parliamentary vote to endorse the GNA and challenging the U.N.-mediated deal to unify Libya.

Haftar also has resisted the GNA's efforts to integrate his self-styled Libyan National Army into the national armed force.

The eastern-based parliament has twice rejected lists of ministers put forward by the GNA's leadership, or Presidential Council, which is meant to represent all sides of Libya's fractured politics.