Libyan strongman Khalifa Haftar insisted Sunday that the mandate of the country's UN-backed government has run out after what he said was the expiration of a tattered 2015 political deal.

The UN-brokered agreement signed in Morocco on December 17, 2015 established Libya's Government of National Accord (GNA) for a one-year period, renewable only once.Despite that deal, Libya has remained divided between the GNA government in Tripoli led by Prime Minister Fayez al-Sarraj and a rival administration backed by Haftar in the east.

In a televised speech Haftar, who has never recognised the GNA's authority, said the "expiry of the Libyan political accord" marked a "historic and dangerous turning point".

"All bodies resulting from this agreement automatically lose their legitimacy, which has been contested from the first day they took office," he said.

The United Nations Security Council on Thursday insisted the 2015 deal remains the "only viable framework" to prepare for elections next year.

The UN in September launched a fresh push to agree a new accord aimed at bringing stability to Libya, which has been in chaos since the 2011 ouster of long-time dictator Moamer Kadhafi.

One of the main stumbling blocks is the inclusion in any potential government of Haftar, whose Libyan National Army dominates the country's east.

In a statement on Sunday the UN's special representative to Libya Ghassan Salame said Libyans were "fed up with violence" and hoped "for a political solution, for reconciliation and for harmony".

"I urge all parties to heed their voices and refrain from any actions that could undermine the political process," the statement said.

The foreign ministers of Tunisia, Algeria and Egypt after meeting in Tunis on Sunday, welcomed the UN Security Council declaration.

They also reaffirmed their rejection of "any outside interference in Libya" and "any attempt by any Libyan party to derail the political process" there.