The Libyan militia leader has not confirmed the claims by Greek Foreign Minister Nikos Dendias.
Greece's government has urged General Khalifa Haftar to agree to a ceasefire in Libya and to condemn a controversial maritime boundary deal with Turkey that has provoked anger in Athens.
Greek Foreign Minister Nikos Dendias said that the government had asked Haftar, who is fighting for control of the war torn north African state against the Turkey-backed government, to "recognise the non-validity of the illegal agreements between Turkey and the (Libyan) government."
Dendias was referring to a deal signed between Libya and Turkey to delineate a boundary between the two countries in the Mediterranean, giving Turkey and Libya access to an economic zone across the Mediterranean despite the objections of Greece, Egypt and Cyprus.
"l must tell you with great pleasure that the commander agreed to all of those remarks," Dendias said, adding that Greece wants Libya "to be a modern country, a modern democratic country.”
Haftar did not comment after the meeting, and headed to another meeting with Greek Prime Minister Kyriakos Mitsotakis. On Thursday, Mitsotakis said that Greece “will never accept a political solution for Libya that does not require the cancellation” of the maritime deal with Turkey.
The meeting comes two days before Haftar heads to Berlin, Germany, for a summit aimed at ending the war in Libya and attended by Vladimir Putin. On Monday, Haftar and his rival Fayez Sarraj, who heads Libya's government in Tripoli met in Moscow, but Haftar - whose rival government is based in Benghazi - declined to sign a ceasefire document.
Speaking on Friday, Turkish President Recep Tayyip Erdogan said he doubted whether Haftar would abide by a ceasefire. “This man is not a trustworthy man,” he told reporters in Istanbul. “Yesterday, they continued to bomb Tripoli.”
Euronews correspondent Apostolos Staikos is following events in Athens. To watch his report, click on the media player above.