Haftar ally UAE backs Egypt peace initiative in Libya
Haftar - who is backed by the UAE and Egypt - also supported the ceasefire proposal, said Egyptian President Abdel Fattah al-Sisi on Saturday following talks in Cairo.
UAE's minister of state for foreign affairs, Anwar Gargash tweeted on Monday that the initiative "strengthens the Arab and international momentum for an immediate ceasefire, the withdrawal of foreign troops, and the return to a political track".
The so-called "Cairo declaration" called for the withdrawal of "foreign mercenaries from all Libyan territory, dismantling militias and handing over their weaponry," Sisi said on Saturday.
But his announcement came as forces loyal to Libya's Government of National Accord (GNA) declared a fresh offensive that aims to take Sirte, the hometown of slain dictator Muammar Gaddafi, in a bid to build upon a string of recent successes against Haftar's men.
The resurgent GNA forces quickly poured cold water on the truce plan, with Mohamad Gnounou, a spokesman, declaring on Saturday that "we will choose the time and place when" the war ends.
The Mediterranean coastal city of Sirte is a key gateway to the country's major oil fields in the east, still held by pro-Haftar forces.
The Turkish-backed GNA based in Tripoli has in recent weeks retaken all remaining outposts of western Libya from pro-Haftar loyalists, who had sought to capture the capital in a 14-month offensive.
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Libya has been mired in chaos since the 2011 uprising that toppled and later killed longtime dictator Gaddafi.
Eastern based Haftar - a 76-year-old former Gaddafi loyalist turned defector who spent years living in the United States - has vowed to rule all of Libya, painting his enemies as jihadists and terrorists.
He has been backed by powers including Russia, the UAE and Egypt with aircraft, high-tech weapons and mercenaries.
Agencies contributed to this report.