Turkey has announced that it will redeploy a research ship to the eastern Mediterranean on Monday, amid an energy row with Greece, news agency AFP reported. Athens has slammed the decision as a “direct threat to peace”.

The two NATO countries staged rival military drills in strategic waters between the Greek island of Crete and Cyprus over the gas exploration row in August.

While Greece claims that it has rights over the waters around the Kastellorizo island, Turkey says that its longer coastline makes the territory a legitimate area for its vessels to explore.

The Turkish navy said the Oruc Reis ship will carry out activities in the region, including the south of Kastellorizo, until October 22 in a message sent to the maritime alert system NAVTEX late on Sunday.

Also read: Turkey, Greece agree to talks on Mediterranean tensions

The vessel will be joined in the latest “seismic survey” mission by two other ships called Ataman and Cengiz Han, the message said.

Turkish Energy Minister Fatih Donmez delivered a defiant message via Twitter on Monday that Turkey “will continue to search, dig and protect our rights”.

“If there is (natural gas), we will absolutely find it,” he said.

But Greece’s foreign ministry on Monday lambasted the move as a “direct threat to regional peace and security” and accused Turkey of being unreliable.

The ministry added in a statement that Ankara did not “sincerely desire dialogue”.

Ankara first deployed the Oruc Reis and warships to disputed waters on August 10 and extended the mission, ignoring repeated calls to stop by Greece and the European Union.

The Oruc Reis was pulled back to shore last month in what many hoped was a sign the two sides could resolve the issue through dialogue.

Turkish President Recep Tayyip Erdogan said at the time that the withdrawal was designed to give diplomacy a chance.

But Turkish officials also insisted the ship was in port for planned maintenance and would return to the eastern Mediterranean to continue its work.

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In his tweet on Monday, Donmez said maintenance work was finished and the ship could now restart its scan of the Mediterranean.

The announcement dashed hopes raised when Turkey and Greece agreed to exploratory talks last month after diplomatic efforts led by Germany to defuse the crisis.

The talks had been stalled since 2016 and the expectation was for their resumption in Istanbul but no exact date was given.

The Turkish and Greek foreign ministers also met last week on the sidelines of a security forum in Slovakia’s capital Bratislava in the highest-level talks since tensions began.

The ministers had agreed that a date should be set for the start of exploratory talks, according to a Greek foreign ministry source.

At a summit earlier this month, the European Union threatened sanctions if Turkey failed to stop what the bloc says is illegal drilling and energy exploration activities in waters claimed by Cyprus and Greece.

Turkey described the threat as “unconstructive” but its latest move will cause further strains in Ankara’s already tense relationship with Brussels.

Also read: Turkey to send ship at centre of Greece row to east Mediterranean again

The German foreign minister is expected to visit Ankara on Wednesday, according to Turkish state broadcaster TRT, where the eastern Mediterranean will be high on the agenda.