Greek and Turkish Cypriots are ready to resume peace talks after a six-month hiatus, the UN envoy announced Tuesday, aiming for a "strategic compromise" this year on the divided island.

The two sides have agreed to start UN-brokered negotiations "within weeks, not months," Norwegian diplomat Espen Barth Eide told journalists in Nicosia.

Eide said talks would not start until after April 19 presidential elections in the breakaway Turkish Republic of Northern Cyprus (TRNC), which could go to a second round the following Sunday.

Cyprus has been divided since Turkey invaded in 1974 in response to an Athens-engineered coup seeking to unite the island with Greece.

Its northern third, still occupied by Turkish troops, later declared itself independent.

The TRNC is recognised only by Ankara, while the Greek Cypriot-controlled Republic of Cyprus is recognised by the international community and is now a member of the European Union.

"My primary focus is a strategic settlement, that is a strategic compromise to be reached," said Eide of a peace process that has repeatedly failed to make headway over the terms of a possible reunification.

"I strongly believe that 2015 will be a decisive year, a decisive year in the right direction."

Eide said Greek Cypriot leader Nicos Anastasiades and his Turkish Cypriot counterpart, Dervis Eroglu, "agree that circumstances are right... Both sides want the dialogue to resume from exactly where it was stopped".

And he added that "there is strong support from the Turkish government towards reunification".

The leaders still have to tackle the thorny issues of property rights, territorial adjustments and power sharing.

They re-launched talks in February 2014 after a two-year gap, pledging to work towards ending the island's division "as soon as possible".

And they agreed any settlement would be based on a "bi-communal, bi-zonal federation with political equality... with constituent Greek- and Turkish-Cypriot states".

In a 2004 referendum, a UN reunification blueprint based on a federal solution was overwhelmingly rejected by Greek Cypriots and approved by Turkish Cypriot voters.

- Tensions over offshore energy -

Asked why the talks have been shelved for so long, Eide replied that "a number of people have been comfortable with no solution," but did not elaborate.

Tensions over offshore exploration for oil and gas had threatened to derail the peace process altogether despite calls from the international community for the two sides to return to the negotiating table.

In October, the Greek Cypriots suspended participation in the latest round of talks to protest what they said were moves by Turkey to undermine their right to exploit gas and oil reserves.

A Turkish ship encroached on Cyprus's exclusive economic zone (EEZ) off the south coast, after Ankara had given notice that a seismic vessel would carry out a survey in the same area where Italian-Korean energy consortium ENI-Kogas is operating.

The Turkish ship has since been withdrawn, paving the way for the talks to resume, Cyprus government spokesman Nicos Christodoulides said.

"We believe... the situation can lead a rational Turkey to realise the benefits of a settlement and hope that by realising these benefits it will work in this direction," he told reporters.

Christodoulides said the UN envoy had assured the president that Turkey would facilitate the peace process and not issue another maritime notice.

"We expect to see this in practise," he said.

"Such a facilitation would see Turkey not proceeding with similar illegal actions... while at the same time substantially supporting the negotiation process."

Turkey's withdrawal from the EEZ coincided with ENI-Kogas and France's Total announcing that they had not found exploitable gas reserves during recent test drills.

ENI-Kogas has asked for a two-year grace period to re-assess its search, while Total will conduct geological surveys instead of drilling.

Ankara opposes Nicosia's exploitation of offshore hydrocarbon reserves before any peace deal, but is itself determined to search for oil and gas in an area where the Cyprus government has licensed exploratory drills.

The Greek Cypriots argue the failure to reach a settlement should not mean such projects are put on hold.