Private military contractor Wagner Group is conducting the hiring with Russian army supervision, opposition sources say.
Forces loyal to Libya’s UN-recognised government said they launched an offensive on Saturday to seize the strategic city of Sirte, as renegade military commander Khalifa Haftar and his Egyptian allies proposed a ceasefire following a string of military setbacks.
“The air force has carried out five strikes in the outskirts of Sirte,” Government of National Accord (GNA) spokesman Mohamad Gnounou said. “Orders have been given to our forces to begin their advance and to systematically attack all rebel positions.”
GNA forces have repulsed Haftar’s 14-month offensive against the capital, Tripoli, and are now poised to drive on eastwards, taking advantage of stepped-up military support from Turkey.
Sirte is the hometown of former longtime leader Muammar Gaddafi and the last major settlement before the traditional boundary between Libya’s west and east.
Haftar’s self-styled Libyan National Army (LNA) forces virtually captured the Mediterranean city of Sirte 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.
Sirte is some 450km (280 miles) east of Tripoli, the town where Gaddafi put up his last stand against NATO-backed rebel forces in 2011.
On Saturday, Egyptian President Abdel Fattah el-Sisi said in Cairo that Haftar and other eastern leaders – including eastern parliament speaker Aguila Saleh – had signed up to a declaration calling for a ceasefire from 6am (04:00 GMT) on Monday.
“Heeding appeals from the major powers and the United Nations for a ceasefire… we pulled back 60km (40 miles) from the Greater Tripoli city limits,” Haftar’s spokesman, Ahmad al-Mesmari, said.
The initiative, called the “Cairo Declaration”, urged the withdrawal of “foreign mercenaries from all Libyan territory”, he said.
Sisi added that the declaration also called for “dismantling militias and handing over their weaponry so that the Libyan National Army [led by Haftar] would be able to carry out its military and security responsibilities and duties”.
But the GNA forces’ spokesman appeared to pour cold water on the Egyptian proposals.
“We didn’t start this war, but we will choose the time and place when it ends,” Gnounou said.
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.
Several countries have expressed support for the Cairo initiative.
In a phone call with his Egyptian counterpart Sameh Shoukry, French Foreign Minister Jean-Yves Le Drian,”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.
The United States said it is “watching with interest” the political voices in eastern Libya where Haftar is based.
“We look forward to seeing these voices incorporated into a genuine nationwide political dialogue immediately following the resumption of the UNSMIL-hosted 5+5 talks on the modalities of a cease-fire,” the US embassy to Libya said in a statement on Saturday.
“We welcome efforts by Egypt and others to support a return to the UN-led political negotiations and the declaration of a ceasefire,” the statement said.
Russia, which, according to UN experts, has employed hundreds of mercenaries from the Russian paramilitary Wagner Group to fight alongside Haftar, also agreed.
“We read the content of the Egyptian president’s offer, of course, we support all kinds of offers to stop the conflicts in Libya as soon as possible,” said Mikhail Bogdanov, Russia’s special representative to the Middle East and African countries, according to the Ria News Agency.
But according to Tarik Yousef, director of Brookings Doha Center, the ceasefire aims to protect Haftar from further military losses.
“In the context of what has just been reported about military advancements in the last week, the series of defeats Haftar has suffered suggest the Cairo initiative is more about trying to salvage what remains of Haftar’s project and trying to protect what remains of his military forces in the east,” Yousef told Al Jazeera.
Libya plunged into chaos after Gaddafi’s killing during the 2011 uprising.
The oil-rich north African country is split between two rival administrations in the east and the west, each backed by opposing fighters struggling for power in the wake of Gaddafi’s downfall.
Haftar has since last year sought to gain control over the west, fighting the GNA in an abortive attempt to seize Tripoli.
LNA forces have in recent weeks lost crucial ground to GNA forces, which are backed by Turkey.
The GNA recaptured the strategic town of Bani Walid in the country’s northwest from the LNA earlier on Saturday.
The latest development comes a day after the GNA seized the city of Tarhuna, Haftar’s last stronghold in northwestern Libya, which was used as the main launchpad against Tripoli.
Friday’s defeat inflicts serious blows to Haftar’s 14-month offensive to capture Tripoli.
Haftar is supported by Egypt, the United Arab Emirates and Russia.