Turkey has warned Cyprus to cancel its tender for oil exploration and drilling rights off the divided island's coast.
"Continuation of the tender process will adversely affect peace and stability on the island of Cyprus", a Turkish government spokesman said.
The first round of licensing involves 11 offshore areas covering a total of about 60,000 sq km (23,000 square miles) to the south of Cyprus.
Ankara says Turkish Cypriots should have a say in oil and gas rights.
The officially-recognised government of Cyprus controls the southern two-thirds of the island.
A Turkish Cypriot breakaway state in north Cyprus is recognised only by the Turkish government in Ankara.
Cyprus has signed deals with Lebanon and Egypt to mark out sea boundaries and make oil and gas exploration easier.