Khalifa Haftar, the Libyan commander whose forces are battling to capture the country's capital from its internationally recognised government, has announced his willingness to open dialogue after repeatedly rejecting United Nations calls for talks, Aljazeera reports.

The statement was issued late on Wednesday. hours after Prime Minister Fayez al-Sarraj called Haftar a "war criminal" and ruled out peace talks during a speech at the UN General Assembly in New York.

"When all is said and done, we need dialogue and we need to sit down" said Haftar.

However, dialogue was "not possible so long as terrorist groups and criminal militias control Tripoli," he said in reference to the myriad of militias that back al-Sarraj's Government of National Accord in the capital.

The move marks a reversal for Haftar, who earlier this month dismissed a UN call for renewed peace talks, saying a military solution was the best way of bringing the conflict to an end. 

He also welcomed the special session to be co-chaired by France and Italy in New York later on Thursday, saying that he hoped it would come up with "proposals that serve Libya's interests and at the same time restore security and stability". 

Libya has been mired in chaos and violence since an uprising toppled and killed longtime leader Muammar Gaddafi in 2011.

In April, Haftar's self-styled Libyan National Army (LNA), which is allied to a rival admnistration in the country's east, launched an offensive to "cleasnse" Tripoli of "terrorists". The operation upended UN-led plans to broker a political settlement in Libya.