Talks in Switzerland on reuniting the divided island of Cyprus have failed to strike a deal, the United Nations has said.

In the latest round of UN-brokered talks in the Swiss resort of Mont Pelerin, Greek Cypriot leader Nicos Anastasiades and Turkish Cypriot leader Mustafa Akinci had been negotiating for two days.

"Despite their best efforts, they have not been able to achieve the necessary further convergences on criteria for territorial adjustment that would have paved the way for the last phase of the talks. The two sides have decided to return to Cyprus and reflect on the way forward," the United Nations said in a statement.

UN Secretary-General Ban Ki-moon opened the talks, saying the leaders were both committed to trying to reach a deal this year.

Cyprus's 800,000 Greek Cypriots and approximately 220,000 Turkish Cypriots live on the divided island, which is split east to west by a UN-patrolled ceasefire line.

Cyprus was split in a Turkish invasion in 1974 triggered by a brief Greek-inspired coup.

But friction between the two sides dates back at least a decade, when Turkish Cypriots pulled out of a power-sharing government at perceived attempts by Greek Cypriots to limit their say.

Mr Anastasiades and Mr Akinci are both moderates leading their respective communities and the negotiations were directed towards reuniting Cyprus as a loose federation of two constituent, largely self-governing states.

Besides territorial swaps, Greek Cypriots who represent Cyprus in the European Union are adamant that a deal see the withdrawal of Turkish forces from the island.

Thousands of Turkish troops are stationed in Cyprus's north, a breakaway Turkish Cypriot state recognised only by Ankara.