Libya's interim leader Mohammad Younes Menfi met with Congolese President Denis Sassou Nguesso, who heads the African Union's committee on the conflict-ridden North African country, to discuss plans for elections in December.

Libya's new transitional executive emerged from a U.N. process that was launched in November in Tunis, then voted on in Geneva and confirmed by Libya's parliament on March 10. Elections are tentatively set for Dec. 24, but many preconditions are yet to be met, Menfi and Sassou Nguesso said in a joint statement.

Ahead of the vote, "urgent challenges (include) the consolidation of the ceasefire, respect of the arms embargo, the unification of the country's military and financial institutions (and) the withdrawal of foreign combatants and mercenaries," the statement said.

"After all that, we will go straight to elections for stability in Libya," Menfi, chairperson of Libya's Presidential Council, told reporters.

The U.N. estimated in December that there were at least 20,000 foreign fighters and mercenaries in Libya, including Syrians, Russians, Sudanese and Chadians.

"It is desirable that President Denis Sassou Nguesso talk directly with the Russian and Turkish presidents to obtain the departure of the mercenaries," a Congolese diplomat told Agence France-Presse (AFP), requesting anonymity.

Sassou Nguesso heads the African Union's High-Level Committee and Contact Group on Libya.

Turkey had backed the Tripoli-based Government of National Accord (GNA) against the eastern-based forces of putschist Gen. Khalifa Haftar that were supported by Russia, Egypt, the United Arab Emirates (UAE) and France.

Libyans hope that the new process will end years of civil war that have engulfed the country since the ousting and killing of strongman Moammar Gadhafi in 2011.