Turkey has resumed energy exploration activities in the eastern Mediterranean Sea, President Recep Tayyip Erdogan said.
"We have resumed the drilling activity," Xinhua news agency quoted Erdogan as saying to reporters after Friday prayers.
He added that Turkey had sent Barbaros Hayreddin Pasa, a Turkish seismographic research and survey vessel, to the area for that purpose.
This week, Egypt and Greece designated an exclusive economic zone between them in the Mediterranean Sea with an agreement signed in Cairo, allowing them to maximize the use of available resources in the zone and tap the oil and gas reserves there.
Referring to the latest agreement, Erdogan blamed Greece for not keeping its promises regarding drilling activities in the region, describing the deal as "worthless".
Turkey and its NATO ally Greece have long been at odds over the energy resources in the region as Ankara has been opposing the drilling efforts of several countries there without its involvement..