Turkish Cypriot leader Mustafa Akinci speaks during a news conference in Geneva, Switzerland January 13, 2017. REUTERS/Pierre Albouy

GENEVA (Reuters) - Talks to resolve the decades-old division of Cyprus ended without agreement on Thursday but with a plan for officials to reconvene on Jan. 18 to tackle the thorny security question, before a fresh attempt to forge a political deal.

U.N. Secretary-General Antonio Guterres told Reuters he was confident that the participants were determined to make a “last effort” to find a solution.

There was no precise date set for the foreign ministers of the three guarantor powers of the process - Greece, Turkey and Britain - to meet again.

“The discussions today underscored the participants’ intention to find mutually acceptable solutions on security and guarantees that address the concerns of both communities. They recognized that the security of one community cannot come at the expense of the security of the other,” said a statement issued by the U.N. from the one-day conference.

“They also acknowledged the need to address the traditional security concerns of the two communities while at the same time developing a security vision for a future united federal Cyprus.”

The east Mediterranean island has been partitioned between ethnic Turks and Greeks since 1974, when Turkish forces invaded in response to an abortive Athens-inspired coup aimed at union with Greece. An accord has eluded generations of diplomats and NATO allies Greece and Turkey have come at times to the brink of war over Cyprus, a former British colony.

“The conference on Cyprus which started today will continue at the level of the technocrats on Jan. 18 to discuss the issue, more specifically the issue of security and guarantees, the concerns which exist and the (various) approaches and when the results are known there will be a continuation of the Cyprus conference with the same composition we had today,” said Greek Cypriot government spokesman Nikos Christodoulides.

Turkish Foreign Minister Mevlut Cavusoglu, speaking to a Geneva news conference, said Turkey’s guarantorship remained “vital” for Turkish Cypriots but there would be a referendum following any agreement.

The two sides had held serious talks on 5 chapters, agreeing on certain topics but leaving other elements still open, he said.