Greece said Monday that Turkey plans to carry out a maritime military exercise on Oct. 28, a Greek national holiday, just hours after NATO’s secretary general said both Greece and Turkey had called off wargames on each other’s national holidays.

Government spokesman Stelios Petsas said Ankara’s move showed it was an “unreliable” partner when it comes to negotiations.

“Over the last few days, Turkey has been making a persistent effort to prove that not only is it a troublemaker in our wider region, but it is also a completely unreliable interlocutor,” Petsas said.

Greek Foreign Minister Nikos Dendias, left, welcomes his Russian counterpart Sergei Lavrov before their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focus on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

Greek Foreign Minister Nikos Dendias, left, welcomes his Russian counterpart Sergei Lavrov before their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focus on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

Neighbors and NATO allies Greece and Turkey have had often frosty relations through the years. Most recently they have been locked in a bitter dispute in over maritime boundaries and energy exploration rights in the eastern Mediterranean Sea.

Turkey has sent a seismic research vessel, the Oruc Reis, to prospect for energy reserves on the seabed in an area Greece that claims is on its own continental shelf and where it has exclusive economic rights. Turkey disputes the claim.

The spat has led to warships from the two sides facing off in the area, leading to fears of open conflict.

Greek Foreign Minister Nikos Dendias, left, welcomes his Russian counterpart Sergei Lavrov before their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focussed on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

Greek Foreign Minister Nikos Dendias, left, welcomes his Russian counterpart Sergei Lavrov before their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focussed on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

On Friday, NATO Secretary-General Jens Stoltenberg said both Greece and Turkey were canceling military exercises scheduled for this week on each other’s national holidays, and described the move as “steps in the right direction, they help reduce the risks of incidents and accidents.”

But Petsas said Monday that hours after that statement was made, Turkey issued a new maritime safety warning, known as a Navtex, announcing a military exercise during Greece’s Oct. 28 holiday.

The day marks the anniversary of Oct. 28, 1940, when Greece rejected an ultimatum by Italy to allow Axis forces to enter Greece, thus marking Greece’s official entry into World War II.

Russian Foreign Minister Sergei Lavrov listens his Greek counterpart Nikos Dendias during their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focus on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

Russian Foreign Minister Sergei Lavrov listens his Greek counterpart Nikos Dendias during their meeting in Athens, Monday, Oct. 26, 2020. The talks of the two diplomats are focus on the situation between Greece and Turkey as the neighbour country announced late Saturday that it is extending by one week a gas exploration mission in the eastern Mediterranean that has caused tensions with Greece. (Costas BaltasPool via AP)

The government spokesman also said Turkey had issued a Navtex for more research to be carried out in an area “covering sections of the Greek continental shelf" south of the Greek island of Rhodes.