In March 2016, GNA chief Fayez al-Sarraj arrived in Tripoli to set up a new government, but the Haftar-allied administration in the eastern city of Tobruk refused to recognise its authority.
His move is the latest in a cycle of conflict and anarchy since the 2011 toppling of former dictator Muammar Gaddafi.
During the meeting, El-Sisi affirmed Egypt's support for the efforts to combat terrorism and extremist groups and militias in order to achieve security and stability for the Libyan citizen in all the country's territory to establish the foundations of a stable and sovereign civil state.
Egypt has close ties with the renegade general but also publicly supports the UN-led peace efforts in Libya. The United Nations has warned the situation could spiral out of control. By moving forces west, his eastern home base is exposed and it may be hard for Haftar to retreat without losing standing among friends and foes alike. Islamist militants have since controlled large parts of the vast country, including the capital Tripoli.
Haftar has defied global calls to halt his battle against fighters loyal to the UN-backed Government of National Accord based in Tripoli.
WHO's Libya account said on Twitter the organisation was sending medical supplies and more staff to Tripoli, and denounced "repeated attacks on health care workers, vehicles" during the fighting which erupted on April 4.
"The humanitarian community is concerned about rising numbers of civilian casualties, including medical personnel", OCHA Libya said.
The United Nations' office for humanitarian affairs said more than 13,500 people had been displaced by the clashes, while more than 900 residents are living in shelters. Both sides have carried out airstrikes on the town, and a spokesman for the Libya National Army said it has stepped up strikes on its rivals in the past two days.
"The humanitarian community repeats its warning that continuing to attack medical and civilian facilities is a violation of global humanitarian law and human rights law", OCHA said in a statement.