"Inviting Haftar to Greece and highlighting the Greek national agenda sabotage the efforts to bring peace to Libya," Çavuşoğlu wrote on Twitter.
"We would like to remind our Greek friends that these futile efforts are in vain. @NikosDendias," he said, referring to the Greek foreign minister who met with Haftar this week.
Putschist Gen. Haftar, commander of Libya's eastern-based forces, on Friday, visited Greece to seek support just two days before the Berlin conference on the Libya conflict, which he and the head of Tripoli's U.N.-recognized Government of National Accord (GNA) Fayez al-Sarraj are expected to attend.
The Berlin conference is set to be a step up by the world powers to provide the lasting of the cease-fire, nine months after an assault on Tripoli by Haftar's forces sparked fighting that has killed more than 280 civilians and 2,000 fighters and displaced tens of thousands.
On Jan. 12, the warring sides of the Libyan conflict announced a cease-fire in response to a joint call by President Erdoğan and Russian President Vladimir Putin.
But talks for a permanent cease-fire deal ended without an agreement on Monday after Haftar left Moscow demanding two days to consult with local Libyan tribes for their approval, while Sarraj signed the cease-fire deal.
Greece seeks to build ties with Haftar after the legitimate government in Libya signed a maritime delimitation and military cooperation deal with Turkey in November.
On Jan. 2, Greece, Israel and the Greek Cyprus administration signed a deal to build an undersea pipeline to carry gas from new offshore deposits in the southeastern Mediterranean to continental Europe.
Turkey strongly opposes the project, which would see part of the 1,900-kilometer (1,300-mile) EastMed pipeline pass through waters it claims under its deal with the Tripoli government.