- German Chancellor gave a sober assessment, insisting that diplomacy was still the best way forward.
BRUSSELS: EU leaders debated the diplomatic crisis with Turkey on Thursday, haggling over the bloc's red lines as they try to defuse a stand-off in the Mediterranean and conflict in Azerbaijan.
The first night of the two-day European Union summit was dominated by the bloc's tricky ties with Ankara, which is embroiled in a dangerous maritime stand-off with Greece and Cyprus.
Greek Prime Minister Kyriakos Mitsotakis insisted as he arrived that recent "provocation" by Ankara must stop, while Cyprus is pushing to broaden sanctions over Turkish drilling for gas in its waters.
After four hours of discussions, the leaders took a break to hold smaller format talks while officials redrafted the text of a summit declaration on Turkey that the Greek and Cypriot leaders wanted beefing up, officials said.
"One thing is certain: Turkish provocation, whether manifested through unilateral actions or through extreme rhetoric, can no longer be tolerated," Greek PM Mitsotakis said.
Ankara has infuriated the EU by sending research ships with naval escorts to work in contested waters, and Athens has responded with war games backed by France, raising fears of full-blown conflict.
Turkey and Greece have agreed to resume long-stalled talks, easing tensions slightly, and on Thursday they set up a military hotline at NATO to avoid any accidental clashes in the area.
But there has been no progress in the row with Nicosia, and Turkey still has vessels in Cypriot waters.
In his summit invitation, European Council president Charles Michel warned that "all options remain on the table" if Ankara does not engage constructively in talks.
French President Emmanuel Macron, who has given full backing to Greece and Cyprus, even to the extent of sending military forces to join Greek war games in the region, reiterated his support, saying "solidarity is non-negotiable".
Options for action could include tough economic sanctions against Turkey, but officials stress that the focus for now is on trying to find a solution through talks.
Despite the growing tensions with President Recep Tayyip Erdogan's government, the EU is wary of alienating an important neighbour, a NATO member which played a crucial role in ending the continent's 2015-16 migrant crisis.
German Chancellor Angela Merkel gave a sober assessment, insisting that diplomacy was still the best way forward.
"I will point out that our relations with Turkey are of course very complex and that the European Union has a great interest in developing a really constructive relationship with Turkey, despite all the difficulties," she said.
EU officials say that as well as brandishing the stick of sanctions threats, they are also dangling the carrot of closer ties if Turkey improves its behaviour.
Further complicating the Turkey talks are allegations of meddling by Ankara in the conflict in Nagorny-Karabakh, where nearly 130 people have been killed in a flare-up between Armenia and Azerbaijan.
Macron alleged that he had seen evidence that Syrian jihadist fighters had used Turkish territory to join the fighting on the side of Azerbaijan.
In Ankara, Erdogan told his parliament that the EU had made itself a "hostage" of the "spoiled Greeks and the Greek Cypriot administration", and vowed not to capitulate.
"We will maintain our determined approach that keep channels of dialogue open until the end," he said.
The Turkey row has had a knock-on effect on Belarus, with Cyprus blocking long-trailed sanctions over the political crisis there to try to get more EU measures against Ankara over its drilling activity.
EU officials have drawn up a list of 40 Belarus officials seen as responsible for rigging the election and cracking down on protests afterwards, and they will face sanctions if Cyprus drops its veto.
According to a draft of the summit's conclusions, seen by AFP, the leaders will call for sanctions to be imposed "without delay".
But, despite Michel holding talks with both Cypriot and Greek premiers before the summit to try to clear the deadlock, diplomats are not optimistic a way out will be found.
The stalemate leaves the EU lagging behind international parters like Britain and Canada, which have already sanctioned Belarus officials including strongman leader Alexander Lukashenko.
While Cyprus has widespread support in its dispute with Turkey, its intransigence on Belarus sanctions has infuriated some countries, with diplomats accusing Nicosia of effectively shielding Lukashenko.