Forces loyal to Libya's UN-recognised government said they launched an offensive Saturday to seize the strategic city of Sirte, as rival strongman Khalifa Haftar backed an Egypt-proposed ceasefire following a string of military setbacks.

Government of National Accord forces have repulsed a 14-month offensive against the capital Tripoli by eastern-based Haftar and are now poised to drive on eastwards taking advantage of stepped up military support from Turkey.

"The air force has carried out five strikes in the outskirts of Sirte," slain dictator Moamer Kadhafi's hometown and the last major settlement before the traditional boundary between Libya's west and east, GNA spokesman Mohamad Gnounou said.

"Orders have been given to our forces to begin their advance and to systematically attack all rebel positions," he added.

Forces of Libya's UN-recognised unity government patrol the town of Tarhuna, southeast of the Tripoli, after retaking it from fighters loyal to eastern-based strongman Khalifa Haftar
Forces of Libya's UN-recognised unity government patrol the town of Tarhuna, southeast of the Tripoli, after retaking it from fighters loyal to eastern-based strongman Khalifa Haftar AFP / Mahmud TURKIA

Sirte was taken by General Haftar's forces virtually without a fight in January after one of Libya's myriad local militias switched sides.

Beyond Sirte lies the prize of Libya's main oil export ports, Haftar's most important strategic asset.

Some 450 kilometres (280 miles) east of Tripoli, the town was where Kadhafi put up his last stand against NATO-backed rebel forces in 2011.

Libyans in the eastern port city of Benghazi watch a televised speech by strongman Khalifa Haftar, whose forces have lost significant ground to a UN recognised government in recent weeks
Libyans in the eastern port city of Benghazi watch a televised speech by strongman Khalifa Haftar, whose forces have lost significant ground to a UN recognised government in recent weeks AFP / Abdullah DOMA

Haftar's forces have put a brave face on their precipitate fallback from the west, saying that it was a response to mounting international pressure for a lasting ceasefire.

"Heeding appeals from the major powers and the United Nations for a ceasefire... we pulled back 60 kilometres (40 miles) from the Greater Tripoli city limits," the general's spokesman, Ahmad al-Mesmari, said.

In Cairo on Saturday, Egyptian President Abdel Fattah al-Sisi, one of Haftar's key foreign supporters, said after talks with the general and other eastern leaders that they had signed up to a declaration calling for a ceasefire from 6 am (0400 GMT) Monday.

But the GNA forces' spokesman appeared to pour cold water on the Egyptian proposals, which included a demand that militias disband and hand over their weaponry to Haftar's men.

"We didn't start this war, but we will choose the time and place when it ends," Gnounou said.

Fighters loyal to Libya's UN-recognised Government of National Accord (GNA) climb over a partially disassembled MiG 23 aircraft, after seizing Al-Watiya airbase southwest of the capital Tripoli, on May 18, 2020.
Fighters loyal to Libya's UN-recognised Government of National Accord (GNA) climb over a partially disassembled MiG 23 aircraft, after seizing Al-Watiya airbase southwest of the capital Tripoli, on May 18, 2020. AFP / Mahmud TURKIA

He issued a "final call" for Sirte's local leaders to abandon Haftar and spare the Mediterranean coastal city "the horrors of war".

"Our forces continue to advance with force and resolve, chasing the fleeing (Haftar) militias," he said.

But the proposal won support from France.

French Foreign Minister Jean-Yves Le Drian, in a phone call with his Egyptian counterpart Sameh Shoukry, "hailed the efforts led by Egypt... and today's result aimed at an immediate halt to hostilities", his ministry said.

"Priority must go to the immediate halt... and rapid conclusion of a ceasefire," the minister stressed.

Sisi urged international support for the initiative and called on the United Nations to invite Libya's rival administrations in the east and the west for talks.

The initiative, which also won support from the Cairo-based Arab League, came after the UN Libya mission said Tuesday that the warring parties had agreed to resume ceasefire talks, following a three-month suspension.

But on Friday, GNA forces celebrated the recapture of Tarhuna, southeast of the capital, Haftar's last western stronghold.

Libya has endured years of violence since the 2011 uprising that toppled and killed Kadhafi, with rival administrations and scores of militias battling for power.

The United Nations has urged outside powers to respect a deal reached at a January conference in Berlin, ending foreign meddling and upholding a much-violated arms embargo.

While the GNA is backed by Turkey and its ally Qatar, Haftar is supported by Russia and the United Arab Emirates as well as Egypt.

In April, UN experts said hundreds of mercenaries from Russian paramilitary organisation the Wagner Group were fighting for him.

But last month, as Haftar's losses mounted, the GNA said Wagner Group fighters had withdrawn from combat zones south of the capital.