The United Nations-backed government of Libya sought on Saturday to reassure its Western supporters by distancing itself from terrorists and extremists.

Some fighters with extremist ties or who have been targeted by United Nations sanctions have said this week that they were joining the Libyan government’s fight against an attack by a militia leader.

The militia leader, Gen. Khalifa Hifter, 75, has long portrayed himself as commanding a fight against terrorism as he has tried to establish himself as a new military ruler of Libya. He has promised an end to the mayhem of warring factions and fiefdoms that has followed the ouster of Col. Muammar el-Qaddafi during the Arab Spring uprising of 2011.

But his critics say his often indiscriminate attacks have only ended up driving more mainstream opponents into alliances of desperation with militants and extremists.