Libya's renegade general belittles the unity government's IS battle

Controversial Libyan General Khalifa Haftar has lashed out at the country's fledgling Government of National Accord after it announced the formation of a new military command to take charge of the battle against the country's Islamic State group affiliate.

Haftar - who leads the Libyan National Army which is loyal to the rival Tobruk administration - slammed the unity government's force as "worthless".

The attack came as world powers said they would lift an arm embargo on the Tripoli government - weapons Tobruk fears might be eventually used on them.

Chief among European and US concerns in Libya is the Islamic State group, which occupies the coastal city of Sirte and has been expanding its territories westwards.

Tripoli forces have launched a new offensive on IS and promises of new weapons to the army from the West are believed to be connected to this fight.

Meanwhile, Haftar's forces have also said they are preparing to battle IS.

"I am not concerned about the GNA... their decisions are just ink on paper," Haftar said in an interview with local media.

"The GNA's military operation against IS is just worthless posturing, I won't waste my time speaking about it. My army is the only legitimate force that can defeat IS," he said.

He accused the Tripoli army of working with Islamist militias which he said "can be put in the same basket at IS".

The Tripoli government contains moderate Islamist political factions and militias tied to them, while Tobruk represents more secular and nationalist groups.

This week, world powers said they would supply Libya's new unity government with weapons to counter the threat posed by IS.

The unity government urged the international community on Thursday to accelerate the arming of its forces - including war planes - after 32 of its fighters were killed in clashes with militants and a car bombing.

Meanwhile, the militant group claimed responsibility for a bombing on Wednesday which according to the military killed at least seven people in Buairat al-Hassun, 60 kilometres west of Sirte.

Twenty-five other members of forces loyal to the GNA were killed in fighting with IS in Abu Grein, a key crossroads further west, the military said.