CRANS-MONTANA, Switzerland — Rival Cypriot leaders meet on Wednesday to resume efforts to solve one of the world’s longest-running political crises in what the island’s UN envoy billed as the "best chance" for peace.

The make-or-break talks in Switzerland are geared towards ending the decades-old division of the island and striking a lasting deal between its Greek- and Turkish-speaking communities.

Despite a daunting list of unresolved disputes, UN envoy Espen Barth Eide said he was confident on the eve of the talks.

"It’s a unique opportunity, because after all of these decades of division it is possible to solve," he told reporters in Geneva.

Cyprus has been divided since 1974, when Turkish troops invaded the northern third of the island in response to an Athens-inspired coup attempt seeking union with Greece.

Turkey still maintains more than 35,000 troops in Cyprus and Nicosia remains Europe’s last divided capital.

The last round of talks in January failed to make any headway, and Eide himself warned that "it is not going to be easy and there is no guarantee of success".

President Nicos Anastasiades, the Greek Cypriot leader who heads the island’s internationally recognised government, and his Turkish Cypriot counterpart Mustafa Akinci will give it another go starting on Wednesday in the Swiss mountain resort of Crans-Montana.

They will be joined initially at least by the foreign ministers from the so-called guarantor powers of Cyprus -- Greece, Turkey and Britain -- along with EU foreign policy chief Federica Mogherini.

Topping the agenda is a new security arrangement for a post-settlement federal Cyprus. This would involve the guarantor powers, which retain the right of military intervention.

The presence of Turkish troops on the island was a major sticking point in previous peace attempts but signs were pointing to a potential breakthrough after a diplomatic source said that Ankara was ready to propose slashing its military presence.

"The Turkish side is willing to reduce troop numbers by 80 percent and put this on the table," said the source.

Eide said the two sides were "basically done" on four other chapters being discussed, revolving around governance and power-sharing, property, economy and EU matters.

Status quo ’not guaranteed’ 

More than 2,000 people went missing during sectarian infighting and massacres carried out by Greek- and Turkish-Cypriot militias that culminated in the 1974 invasion.

Eide said that while there was currently no "burning drama" in Cyprus, "many Cypriots are aware that the status quo is not guaranteed".

UN chief Antonio Guterres, who may end up attending the Crans-Montana talks, said in New York on Tuesday that the chance to reunify Cyprus "is now finally before us".

But some analysts doubt that the two sides can broach considerable gaps in how a unified Cyprus would actually function.

"What we can hope for is progress on the security chapter," said Hubert Faustmann, a political science professor at the University of Nicosia.

"Anything less" than a security deal that saw some Turkish troops remain on the island would be rejected by Ankara "and the conference will fail," he said. — AFP