Mitsotakis' comments came during a TV interview as rogue Libyan General Khalifa Haftar, whose forces are battling the Tripoli government, was scheduled to arrive in Athens for talks.



Greece objects to the maritime border deal signed between the Tripoli government and Turkey, which grants Ankara rights to vast swathes of the eastern Mediterranean thought to contain potentially rich natural gas deposits. Athens also claims rights over the area.



Mitsotakis described the deal as "unacceptable and illegal" in his interview on private Alpha TV, adding that he has conveyed his intentions on blocking a potential peace deal to senior European officials.



A number of European officials are due to meet in Berlin on Sunday for a summit on the future of the Libyan conflict.



Turkey and Russia, which have led an independent ceasefire effort, will also attend, but Greece has not been invited.



"Greece, at the level of a [European Union] summit meeting, will never accept any political solution on Libya that does not include as a precondition the annulment of this agreement," Mitsotakis said.

"To put it simply, we will use our veto even before the matter reaches the summit, at the level of [EU] foreign ministers," he said.



Relations between neighbours Greece and Turkey have already deteriorated considerably over the past year over the issue of undersea exploration and drilling rights in the Aegean Sea, off Cyprus, and in areas off the southern Greek island of Crete.



The EU has previously threatened Ankara with sanctions over exploration off the coast of Cyprus, with Turkey sending warship-escorted drill ships into waters where Cyprus has exclusive economic rights.



On 2 January, Greece, Israel and Cyprus 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 Prime Minister Fayez al-Sarraj's government in Tripoli.



Mitsotakis also said Athens was very disappointed not to have been invited to Sunday's international summit on Libya in Berlin.



"It was wrong that we were not invited," Mitsotakis said. "We have sea borders with Libya and should have been at Berlin."



Turkish President Recep Tayyip Erdogan said on Thursday Ankara would begin offering licenses for gas exploration and drilling in the eastern Mediterranean later this year.



On Friday, Haftar is due to continue meetings in Athens with Mitsotakis as well as other senior Greek officials after having met with Foreign Minister Nikos Dendias on Thursday.

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