ATHENS — SYRIZA-Progressive Alliance party leader Alexis Tsipras called on the EU to stand on par with the current predicament of Turkish illegal actions in the Eastern Mediterranean and decide on measures against it at the EU Summit that began in Brussels on Thursday.

"Over the last four months Turkey pursued the most aggressive actions against Greece in the last 25 years, carrying out maritime research only a few nautical miles off the islands of Rhodes and Kastelorizo," he wrote in social media.

The EU should impose sanctions on Turkey as the country violated the sovereign rights of an EU member state, he stressed.

The main opposition party leader then referred to his September letter to European heads of state, in which he had pointed out that a viable dialogue with Turkey is not feasible unless the European bloc shows "it doesn't step back in the face of blackmail and provocations," especially so when these come from a country hoping to eventually join the bloc, he underlined.