- Tensions flared in August when Turkey - a NATO ally and candidate for EU membership - sent a survey vessel to map out energy drilling prospects in waters also claimed by Greece.
BRUSSELS: European Union foreign ministers evaluated grounds on Monday for sanctions against Turkey over a Mediterranean gas dispute before the bloc's leaders decide at a summit on Dec. 10-11 whether to make good on their threat to impose punitive measures.
Turkish President Tayyip Erdogan said his country would not "bow down to threats and blackmail" but repeated his call for negotiations over the conflicting claims to continental shelves and rights to potential energy resources.
Tensions flared in August when Turkey - a NATO ally and candidate for EU membership - sent a survey vessel to map out energy drilling prospects in waters also claimed by Greece.
Germany, current holder of the EU's six-month presidency, holds the key to whether sanctions go ahead. It had hoped to mediate between Athens and Ankara, but was angered when Turkey resumed its gas exploration off Cyprus in October after a pause.
"There have been too many provocations, and tensions between Turkey, Cyprus and Greece have prevented any direct talks," German Foreign Minister Heiko Maas told reporters in Brussels.
"For this reason, we will talk about what consequences we should draw - also with a view to the EU summit this week."
EU leaders told Turkey in October to stop exploring in the disputed eastern Mediterranean waters or face consequences.
France and the European Parliament, which formally called for sanctions on Nov. 26, say it is time to punish Turkey, which is seen in Brussels as fuelling the dispute for domestic political reasons.
Greece has said it will not begin formal talks with Turkey over maritime claims while Turkish vessels remain in the contested waters.
"Turkey must demonstrate, in practice, that it supports the idea of this dialogue," Greek Foreign Minister Nikos Dendias said on Twitter late on Sunday. "However, this choice on Turkey's part must have continuity."
The Turkish vessel, Oruc Reis, returned to port again last week, helping to calm tensions, but European Council President Charles Michel warned Turkey not to play "cat and mouse" by returning exploration ships to port just before EU summits, only to redeploy them after they had finished.
EU officials say broader issues of disagreement - over Libya, Syria, Russia and Turkey's own drift towards authoritarianism - have hardened European positions towards Ankara.