Nicosia persuaded EU leaders at the summit in Brussels on Thursday (23 October) to criticise Turkey for violating its economic zone and sovereignty.

“We are convinced that, without a strong collective message, Turkey will continue escalating the situation,” said Cypriot president Nicos Anastasiades.

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Turkey has occupied the northern part of Cyprus since 1974 (Photo: Michael Kirian)

Anastasiades, who was unable to attend the meeting due to a sudden illness, delivered his message via Greek prime minister Antonis Samaras.

Turkey occupied northern Cyprus in 1974 in response to a Greek-led coup, creating the longest-running frozen conflict in Europe.

Earlier this week, Ankara dispatched a ship to look for hydrocarbons off southern Cyprus.

Greek Cypriot authorities say the vessel, flanked by Turkish warships, entered their exclusive economic zone on Monday morning. The boats were spotted 20 miles off the easternmost part of Cyprus' southern coast.

The move has further aggravated tensions, as Cyprus views the offshore gas reserves as a potential way out of its economic malaise. It has already licenced some of the zones to multinationals like Italy’s ENI.

Estimates suggest there are some 5 trillion cubic metres of gas to be pulled out.

For their part, EU leaders are set to express “serious concern” over Turkey's actions in a joint statement on Friday.

"The European Council expressed serious concern about the renewed tensions in the eastern Mediterranean. It called on Turkey to respect Cyprus' sovereign rights," a draft of the text - obtained by EUobserver - says.

It adds a warning that Turkey will never get into the EU until the conflict is resolved.

“The European Council recalled … that the recognition of all member states is a necessary component of the accession process”.

Meanwhile, across the Atlantic, US state department spokesperson Jen Psaki on Thursday gave a modest assessment of Turkey’s incursion.

She said the Americans recognise Cyprus’ right to develop its resources in its exclusive economic zone, but she noted the “island’s oil and gas resources, like all of its resources, should be equitably shared between communities in the context of an overall settlement”.

The decades-long saga has seen Cyprus and Turkey start and stop UN-led negotiations on how to end the standoff.

Greek Cypriots say the wealth generated by the hydrocarbons could be shared with their Turkish Cypriot counterparts if a peace deal is ever reached.

Turkey, for its part, does not recognise the maritime area as an economic zone exclusively reserved for Nicosia. It says Cyprus must not begin to exploit the zone without first agreeing a peace deal.

UN brokered talks between the two broke apart earlier this month after Ankara announced plans to search for gas and oil off Cyprus' coast.

But whatever happens with its EU accession process, Turkey, a Nato member, is seen by Western leaders as a strategic partner in terms of Middle East relations, succour for Syrian refugees, and the fight against Islamic State.

The European Commission earlier this month recommended opening two new chapters in Turkey accession talks in a decision backed by France.

The move came despite Turkey's crackdown on civil liberties and its defenestration of judges, prosecutors, and senior policemen who tried to investigate corruption allegations against the ruling clan of president Recep Tayyip Erdogan.