Greece pressed its European Union partners to draw up “severe” sanctions against Turkey over its energy exploration in the eastern Mediterranean, a move that could unlock separate EU efforts to penalize Belarus.

A Cypriot proposal from June to add seven Turkish entities to the EU’s sanctions list has been moving at a snail’s pace, as some member states fret over further antagonizing Ankara

Greek Alternate Foreign Minister Miltiades Varvitsiotis said Turkey’s hunt for natural gas in waters claimed by Greece and Cyprus is part of aggressive geopolitical posturing by the Turkish government.

“Turkey is a major destabilizing factor in the wider area,” Varvitsiotis told a European Parliament committee in Brussels on Thursday. “This should be an issue of concern for the EU and the international community.”

Cyprus has warned peers it won’t sign on to an EU proposal to sanction dozens of officials in Belarus over that country’s contested presidential election, unless member states agree to clamp down on Turkey following to its drilling activities, people familiar with the matter said. Foreign policy decisions in the EU require unanimity among the bloc’s 27 national governments.

Strains between Turkey and Greece over contested territorial waters have worsened in recent weeks following heightened Turkish tensions with Cyprus. The Turkish-Greek dispute has sparked concerns about a military confrontation between two North Atlantic Treaty Organization members and prompted a German-led diplomatic push for a resolution.

Greece maintains that islands must be taken into account in delineating a country’s continental shelf, in line with the United Nations Law of the Sea, which Turkey has not signed. Ankara argues that a country’s continental shelf should be measured from its mainland, and that the area south of the Greek island of Kastellorizo -- a few kilometers off Turkey’s southern coast -- falls within its exclusive economic zone.

The EU is engaged in a balancing act over Turkey, seeking to defend the sovereignty of member countries Greece and Cyprus while holding out hope that diplomacy can ease tensions with a strategically important partner. Turkey plays a key role in limiting the risk of a new influx of refugees into the EU.

In a largely symbolic act in February, the bloc imposed asset freezes and travel bans on two employees of Turkish Petroleum Corp. in response to Turkey’s energy exploration off Cyprus. EU leaders are due to focus on relations with Turkey at a Sept 24-25 meeting in Brussels.

A Cypriot proposal from June to add seven Turkish entities to the EU’s sanctions list has been moving at a snail’s pace, as some member states fret over further antagonizing Ankara.