Top foreign diplomats to join rival leaders in Cyprus reunification talks

International diplomats are set to join the rival leaders of ethnically split Cyprus for talks that the UN says are the best chance to reunify the island after four decades of division.

British foreign minister Boris Johnson, as well as his Greek and Turkish counterparts, will attend Cypriot-led negotiations in Geneva on Thursday.

The goal is for the two sides to share power in a two-state federation.

The strategically located island in the eastern Mediterranean, a former British colony, was split after a Turkish invasion in 1974 triggered by a brief Greek-inspired coup. Turkey still has 30,000 troops stationed in the island's north.

Greek Cypriot and Turkish Cypriot leaders on Wednesday exchanged maps proposing territorial boundaries.

It was the first time they had done so, according to the UN, and was hailed as an important advance on the path towards a deal.

Britain, Turkey and Greece are guarantor powers of the independence of Cyprus, allowed to intervene to restore constitutional order under a 1960 treaty.

New UN Secretary General Antonio Guterres is also attending the talks in Geneva, his first foreign trip in the role.

Reaching a deal is possible, according to Espen Barth Eide, the UN special adviser on Cyprus, though he cautioned that "some of the most complicated and emotional issues" remained outstanding.

While it is unlikely that a "comprehensive settlement" will be agreed in these talks, diplomats and negotiators "will go home with a sense that it is coming", he told reporters.

The maps presented on Wednesday and now locked in a UN vault will form the basis for future discussions on boundaries dividing zones in a federal Cyprus, the BBC reported.