The United Nations and the European Union have asked Turkey and Cyprus to show restraint in a dispute over gas exploration rights in the Mediterranean.

A spokeswoman for EU foreign policy chief Catherine Ashton on Monday called on both sides to reach a settlement as soon as possible.

Turkish Energy Minister Taner Yildiz warned earlier Monday that his country would start oil and gas exploration in the eastern Mediterranean escorted by the Turkish navy next week if Cyprus presses ahead with its drilling plans. The Greek Cypriot government announced last month it is planning to begin exploration of oil and gas reserves off the island's coast. U.S.-based Noble Energy will also work on the project.

Turkey's government does not recognize Cyprus, which has been divided since 1974 between a Turkish-controlled north and a Greek Cypriot south.

In a related issue, Turkey has threatened to freeze relations with the European Union if it gives Cyprus the sixth-month rotating EU presidency next year.

The internationally recognized Greek Cypriot government is due to take on the six-month rotating EU presidency next July.

Greek Cypriots represent the island internationally, while Turkey is the only country in the world that recognizes the Turkish Cypriot north of the island.

Cyprus was split in a 1974 Turkish invasion triggered by a Greek-inspired coup. Turkish Cypriots live in its north and Greek Cypriots in the south. Ongoing reconciliation talks begun in 2008 between the Turkish north and the Greek south have so far failed to produce a settlement.