Turkey is fuelling tensions and making “unacceptable” comments questioning Greece’s sovereignty in the Aegean Sea, Greek Prime Minister Kyriakos Mitsotakis said.

“Turkey is provoking tension and portraying Greece as an alleged aggressor,” Mitsotakis said during a press conference Sunday, Greek daily Kathimerini reported. He added that “there is no one abroad who believes that the Greek islands are a threat to Turkey.”

His comments come after Turkish President Recep Tayyip Erdoğan earlier this month accused Greece of occupying demilitarized islands in the Aegean Sea. He said that Turkey was ready to “do what is necessary” when the time comes.

“I find the recent statements of the Turkish president unacceptable,” Mitsotakis said on Sunday, warning that “the constant provocation” by Turkish politicians “is extremely problematic.”

Tensions escalated on Saturday after the Turkish interior ministry issued a statement accusing the Greek Coast Guard of firing at a cargo ship sailing in international waters southwest of the Turkish island of Bozcaada. No injuries were reported.

The Greek prime minister said that he “cannot imagine a Greek-Turkish conflict with Turkey attacking” and that he is “always open to meeting Erdoğan.”

“We will always try to keep communication channels open,” Mitsotakis said.