ATHENS, Greece (AP) — Greece’s prime minister accepted an invitation to hold talks with Turkish President Recep Tayyip Erdogan in Istanbul on Sunday, a rare meeting as their nations remain at odds over issues such as migration, minority rights and maritime boundaries.

Greek Prime Minister Kyriakos Mitsotakis planned to be in Istanbul to meet the spiritual leader of the world’s Orthodox Christians, Ecumenical Patriarch Bartholomew, who is based in Turkey’s largest city.

“It’s our longstanding position that the door to dialogue must remain open, just as the door to threats must remain closed,” Mitsotakis said Wednesday of his scheduled meeting with Erdogan.

Turkey and Greece both belong to NATO. However, a dispute over drilling rights for potential oil and gas deposits in the eastern Mediterranean Sea led to a tense naval standoff in the summer of 2020. Greece has since embarked on a major military modernization program.

But the two countries also cooperate on energy projects, including a newly built pipeline that transports natural gas from Azerbaijan to western Europe. The pipeline, which crosses Turkey and Greece, is part of Europe’s effort to reduce dependence on Russian energy.