The UN-backed Libyan Government of National Accord (GNA) will agree to a ceasefire to end the conflict only if Khalifa Haftar withdraws his forces from key central and western regions, especially from Sirte and Jufra, Turkey’s foreign minister has told The Financial Times.

Mevlut Cavusoglu told the Financial Times on Saturday that there was a determination within the Tripoli-based GNA to resume its offensive against Haftar’s forces if they do not retreat from Sirte, a strategic port city, and Jufra, home to a large airbase in the centre of the country.

Cavusoglu's comments underline the threat that the conflict in Libya, which has morphed into a proxy war, could enter a new phase even as diplomats warn that an escalation would risk triggering a direct confrontation between foreign powers backing rival Libyan factions.

Speaking about Al-Watiya airbase strikes, Cavusoglu said there was an investigation to determine who was responsible, but vowed that whoever it was, they will pay, adding that Turkey had trainers and technical staff at the base, but none were harmed.

Cavusoglu indicated that Russia presented a ceasefire offer during talks in Istanbul last month with a “concrete date and time”, but when Ankara consulted with the GNA, the Libyan officials stated their preconditions on Sirte and Jufra and for Haftar’s forces to return to “lines” they held in 2015.

“Now it depends on the other side, they should accept these preconditions for a lasting ceasefire." Cavusoglu told The Financial Times.