NICOSIA (Reuters)-Turkey will never abandon its rights as a "guarantor" power on Cyprus, even if a peace deal is signed between Greek and Turkish Cypriot leaders later this year, Turkish Deputy Prime Minister Cemil Cicek said on Monday.

Cicek was speaking in northern Cyprus on the 35th anniversary of Turkey's invasion of the island, which took place five days after a brief Greek-inspired coup.

Turkey attempts to justify its military invasion by its status as a guarantor power, with Greece and Britain, under the 1960 treaty that gave Cyprus its independence from London.

The guarantor rights - effectively meaning that any of the three can intervene to restore constitutional order - are a key sticking issue in slow-moving peace talks between the Greek and Turkish communities on the divided island.

"Only a solution that reflects the realities of two peoples and two states is possible. It must also include Turkey's effective guarantor rights," Cicek said. "Turkey will never renege on its guarantor obligations."

Greek Cypriots insist the guarantor provisions be ditched, and Turkish Cypriots that they must be maintained. For Greek Cypriots, who want reunification as a bizonal federation, the Turkish call for a two-state deal is also a non-starter.

Across a United Nations-controlled ceasefire line in Cyprus's south, the anniversary of the invasion was marked by Greek Cypriot air raid sirens piercing the silence just before dawn, marking the hour Turkish troops landed on the island.

Reunification talks were launched in September 2008, with diplomats hoping the process can end a decades-old conflict which is complicating Turkey's bid to join the European Union.

The diplomats want the talks concluded before Turkish Cypriot presidential elections in April 2010. Greek Cypriots represent Cyprus in the EU, and will not consent to Turkey joining the bloc as long as the island is split.

"It is true that we are not far from a settlement, but we have to proceed carefully and quietly...to avoid disappointment again," Turkish Cypriot leader Mehmet Ali Talat said.

At a memorial service for the Greek Cypriot victims of the invasion on the other side of Cyprus's divide, Greek Cypriot leader Demetris Christofias said: "It is a fact that we have diametrically opposing views."

Previous reunification efforts on Cyprus collapsed in 2004 when Greek Cypriots rejected a settlement blueprint accepted by Turkish Cypriots.

"The window of opportunity will not stay open indefinitely," Cicek said.