Cyprus on Monday accused Turkey of interfering in its oil exploration and protested that a Turkish warship had impeded a Norwegian-flagged exploration vessel off the island's coast earlier this month.
"We have made all the necessary protests and taken every conceivable action," Foreign Minister Marcos Kyprianou told reporters after the Nov. 13 incident was made public.
"Such moves by Turkey are illegal according to international law and violate the very principles of international law. Certainly we are not going to accept this," he said.
He said a formal protest was lodged with U.N. and the European Commission over the incident said to have occurred in Cyprus's economic exclusion zone.
The authorities say the "confrontation" took place when two Turkish naval ships stopped a Norwegian exploration vessel, commissioned by the Cyprus government, in open waters off the coast of Paphos and forced it to turn back.
"We are monitoring this situation very closely to protect and exercise our international rights of the sea and economic interests," government spokesman Stephanos Stephanou told state radio.
The incident occurred on the same day as Cyprus's Greek Cypriot President Demetris Christofias and Turkish Cypriot leader Mehmet Ali Talat continued negotiations in a U.N.-brokered bid to reunify the island after decades of division.
Cyprus has received applications for oil exploration permits for a 70,000-square-kilometer (27,000-square-mile) area in the Mediterranean south and southwest of the island.
Officials say provisional data indicates there are substantial oil and gas deposits in a sea area separating the island from Egypt and Lebanon.
The issue has caused friction between Turkey, Egypt and Lebanon and raised tensions in the region.
Cyprus has signed gas and oil exploration and exploitation deals with Egypt and Lebanon, prompting protests from Turkey. It plans to eventually open 11 blocks for hydrocarbon exploration, although a contract has yet to be awarded.
Last year, Turkey reacted angrily to Cyprus tendering licences for exploration.
Nicosia said it wouldn't be intimidated into scrapping bids for oil drilling off its shores, adding that it was exercising its sovereign rights within the framework of international law.
Cyprus, an E.U. member state, has been divided since 1974 when Turkey seized and occupied the northern third in response to an Athens-engineered coup in Nicosia seeking to unite the island with Greece.