This comes less than a month after EU leaders warned Turkey to end its gas drilling in waters around the island or face action from the bloc, after Greece and Cyprus pressed other EU states to speak out.
Cyprus, an EU member, has discovered natural gas in areas off the south of the island, though nothing has been extracted.
Turkey disputes the rights of the island to explore for gas, sending drill ships of its own to stake a claim around the island.
In this context, another Turkish vessel, 'Fatih', has been on the west of Cyprus, in an area Cyprus claims is its Exclusive Economic Zone (EEZ), since early May.
Turkey’s declared intention to illegally conduct a new drilling operation northeast of Cyprus is of grave concern. This second planned drilling operation, two months after the start of the ongoing drilling operations west of Cyprus, is a further unacceptable escalation which violates the sovereignty of Cyprus,
...said Vice-President of the European Commission Federica Mogherini in an official statement.
We call on the Turkish authorities, once again, to refrain from such actions, act in a spirit of good neighbourliness and respect the sovereignty and sovereign rights of the Republic of Cyprus in accordance with international law.
Meanwhile, the President of Cyprus Nicos Anastasiades raised the issue during a meeting with the Special Representative of the UN Secretary-General in Cyprus, Elizabeth Spehar, Wednesday, 10 July.