A U.N. envoy has said he sees an opportunity to resume suspended talks to reunify the ethnically divided island of Cyprus amid signs that the clash over offshore natural gas exploration may be ebbing.U.N. Special Advisor for Cyprus Espen Barth Eide said that after talks with Greek Cypriot President Nicos Anastasiades on Tuesday that the reasons that led to a halt in talks may no longer exist and gas developments could create "a climate where talks can continue."Meanwhile, Anastasiadis has reportedly asked Russia to be a mediator with President Recep Tayyip Erdoğan on the reunification of Cyprus, which has been a center of dispute since the discovery of natural gas. According to Greek daily Kathimerini, Anastasiadis offered a "win-win" formula to Erdoğan via Russian President Vladimir Putin over the island's hydrocarbons, if Ankara shows cooperation. The daily asserted that Greek Cyprus asked Russia to mediate to prevent possible critical dilemmas in case of a failure to reunite the island.In his message to Erdoğan, Anastasiadis highlighted the significance of reviving the Cyprus negotiations to create a dialogue on the island in an attempt to reach a positive solution. Greek Cyprus's move has been interpreted as the Greek side giving up on the mediation carried out by Greece, the U.S. and U.K.The ongoing dispute on the island started in the 1960s when a Treaty of Guarantee was signed between Turkish and Greek Cypriots on the island along with the British government. The treaty stipulated that Cyprus would not participate in any political or economic union with other states, but three years later, Turkish Cypriots were ousted by force from all bodies of the new republic by Greek Cypriots. Later, Greek Cyprus claimed to be the representative of the island, calling itself the Republic of Cyprus, which is not recognized by Turkey.All efforts by the international community to end the dispute between 1964 and 1974 failed. When the Greek side tried to annex the island in a coup in 1974, a Turkish peace mission was launched in accordance with the 1960 treaty to prevent it from happening.Cypriots went to the polls in 2004 to vote on the Annan Plan for Cyprus, which was a U.N. proposal to resolve the dispute by restructuring the island as a "United Republic of Cyprus." It proposed a federation of the two states that aimed to unify the Turkish and Greek Cypriot communities.The proposal was revised five times before it was put to a referendum in April 2004. It was supported by 65 percent of Turkish Cypriots and 24 percent of Greek Cypriots, who claimed that the proposal favored Turkish Cypriots. Last February, reunification talks were revived in the U.N. Buffer Zone in an attempt to unite the island once and for all. However, the talks stalled when Turkey sent the survey vessel Barbaros Hayrettin Pasha to the area where Greek Cyprus intended to conduct exploratory drilling for oil and gas.