Published: Sep 19, 2011 4:27 PM EDT

NICOSIA, Cyprus (AP) - A U.S. energy firm has begun exploratory drilling for oil and gas off the coast of Cyprus despite strong warnings from Turkey not to do so.
    
Noble Energy, based in Houston, is now smack in the middle of an escalating dispute over mineral deposits in the eastern Mediterranean, complicated by the status of Cyprus. The island has been divided since 1974 into an internationally recognized Greek Cypriot south and a breakaway Turkish Cypriot north, which is recognized only by Turkey.
    
In dispute is not only where any future energy revenues flow, but who has the right to what undersea riches when the status of the nearby land itself is unresolved.
    
Cypriot energy chief Solon Kassinis told The Associated Press on Monday that workers on a Noble rig have already drilled 260 feet (80 meters) beneath the seabed about 115 miles (185 kilometers) off the island's southern coast.
    
In a significant escalation of tensions, Turkey said earlier Monday it would send warships to protect its claims to undersea resources off Cyprus if the U.S. firm began drilling.
    
After the news, Turkish Prime Minister Recep Tayyip Erdogan issued a new warning.
    
Turkish "frigates, gunboats and its air force will constantly monitor developments in the area," he said, adding Turkey will begin its own oil and gas search as early as this week.
    
The area in question is near sizable gas finds within Israeli waters, and within Cyprus' exclusive economic zone - an area marked out following agreements with Egypt, Israel and Lebanon delineating Mediterranean undersea borders to facilitate the search for mineral deposits.
    
The Turkish government does not recognize the Cypriot government in the south, and vigorously protested the August announcement of Noble's intentions. Turkey says the Greek Cypriot drilling can derail long-running talks to reunify the island.
    
"This exclusive economic zone is disputed and we have told them that it is not right for them to take such a step in this area," Erdogan told reporters Monday.
    
Turkish Energy Minister Taner Yildiz said unless Cyprus halted the drilling, his country would send its own energy research ship out escorted by the Turkish navy.
    
"This work will be carried out together with the escort," Yildiz told reporters. "There will be no turning back on this issue."
    
Turkey has been pursuing an increasingly muscular foreign policy since the re-election of its religiously rooted government in June. It expelled the Israeli ambassador this month in a dispute over a deadly Israeli raid last year on a Turkish aid convoy to the Gaza Strip and pledged to send its navy to escort future aid convoys.
    
Cyprus' President Dimitris Christofias on Sunday accused Turkey and Turkish Cypriots of "clamoring needlessly," saying it would take another year until experts can determine the quality of the deposits and the feasibility of extracting them.
    
"If they truly want to jointly exploit this seaborne treasure that nature granted us, they have to seriously sit at the negotiating table," Christofias told Greek Cypriots in London. "If and when the Cyprus problem is solved, we will share this gift."
    
Christofias reiterated his country's position that any agreement between Turkey and the breakaway Turkish Cypriot state to search for offshore deposits would contravene international law.
    
"They can't talk about the rights of the illegal state," he said.
    
Turkey had discussed the issue with U.S. officials but not with the company itself, Yildiz said, adding that the risks for Noble were considerable.
    
Turkey has also renewed threats to freeze all ties with the European Union if Cyprus is allowed to assume the presidency of the 27-nation group next July before a settlement that would allow the Turkish north to be a legitimate representative of the reunified state.


(Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)