Greek and Turkish Cypriot leaders have exchanged maps outlining rival territorial proposals in a development that increased hopes for a solution to the Cyprus dispute.

Presented, submitted and then sealed in a UN vault in Geneva on Wednesday, the territorial adjustments could form an integral part of solving a decades-old conflict that has kept Greece and Turkey at loggerheads and obstructed Turkey's membership bid to the EU.

Turkish Cypriot leaders have agreed in principle to return some of the land they have controlled since a 1974 invasion by Turkish troops, which came in response to a coup by armed Greek Cypriots seeking union with Greece.

"Never before have we had an exchange of maps, or a presentation of maps, created by the delegations themselves," Espen Barth Eide, the UN envoy for Cyprus, said before the handover.

Eide said the talks, aimed at creating a bizonal state with some form of shared central administration, were on track.

"We have dealt with some of the most difficult issues. We have touched upon almost all of them, we have solved many of them and we are close to resolving some other issues," Eide said.

Emotions still run high over issues such as territorial exchange and restoration of property lost on both sides as the island was partitioned amid bloodshed in 1974.

'Turkey's stance important'

Analysts and diplomats say Greek Cypriot leader and President Nicos Anastasiades and Turkish Cypriot leader Mustafa Akinci, two moderates, have a unique opportunity to settle a dispute which has dragged on for decades.

According to Andreas Theophanous, a former advisor to the president of Cyprus in the 1990s, the key to solving the Cyprus question is the stance of Turkey.

"If Turkey respected the independence of Cyprus in the past, we would have made more progress today," he told Al Jazeera from Nicosia.

"The issues raised by Ankara and the Turkish Cypriot side make it really hard to reach a solution, issues such as a member of the EU, Cyprus, having security guarantees from Turkey, Turkey not recognising Cyprus as a country and presence Turkish troops on the island."

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Turkish analyst Musaffer Senel told Al Jazeera from Istanbul that both sides, though they do not often say it publicly, are optimistic about resolving the dispute.

"It is not Ankara or Athens negotiating in Geneva, it is Greek and Turkish Cypriot leaders. And the political will of these parties is the most important thing that will bring us to a possible solution," he said.

The foreign ministers of Greece, Turkey and Britain, guarantor powers of Cyprus's independence, were due in Geneva on Thursday to discuss the security parameters of any deal. The new UN chief Antonio Guterres will attend the talks in Geneva on the same day.

Key issues

Turkey has around 30,000 troops in northern Cyprus. Their presence is strongly contested by the Greek side, which says a deal is not possible without them pulling out.

The Greek Cypriots want the guarantor system dismantled, calling it an anachronism which could keep the island under the perpetual influence of Turkey. Turkish Cypriots, fearful of past experiences since the 1960s when they were targeted by Greek Cypriot nationalists, want Turkish guarantees to continue.

Any adjustment would modify the existing ceasefire boundary splitting Cyprus east to west and decreasing territory under Turkish Cypriot control, which is about 36 percent today.

Past peace negotiations have reached a ballpark range of between 28.2 and 29.2 percent of Cypriot territory remaining under Turkish Cypriot control.

There are about 800,000 Greek Cypriots and 220,000 Turkish Cypriots.

Greek Cypriots want an arrangement which would see the maximum possible number of their internally displaced returning to their homes under Greek Cypriot control.

The 1974 invasion uprooted 165,000 Greek Cypriots, while about 40,000 Turkish Cypriots were displaced in intercommunal violence in the 1960s and a population transfer in 1975.