Talks aimed at ending the decades-old conflict on Cyprus have been temporarily suspended at the request of the two sides, but were expected to resume later Wednesday, the United Nations said.
Cyprus is one of the world's longest-running political crises and the UN-backed talks that began in the Swiss Alpine resort of Crans-Montana a week ago have been billed as the best chance to end the island's 40-year division.
But the talks, which are being headed by President Nicos Anastasiades, the Greek-Cypriot leader, and his Turkish-Cypriot counterpart Mustafa Akinci, were put on hold on Wednesday morning.
"The morning meetings have been postponed until late afternoon at the request of the two leaders to allow time for prep work and consultations," Aleem Siddique, spokesman for UN mediator Espen Barth Eide, told AFP in an email.
He said Eide would hold a series of bilateral meetings before talks resume at 6:00 pm (1600 GMT).
The eastern Mediterranean island has been divided since 1974 when Turkish troops invaded and later occupied its northern third in response to an Athens-inspired putsch seeking union with Greece.
Greece, Turkey and Britain, which are Cyprus's so-called guarantor powers, also have delegations taking part in the talks in Switzerland.
UN Secretary General Antonio Guterres last week hailed the talks as "highly constructive", and urged the rival Cypriot sides to seize "a historic opportunity to reach a comprehensive settlement to the conflict that has divided Cyprus for too many decades".
But the tone at the meetings has since appeared to sour over the tricky issue of security, with Greek Foreign Minister Nikos Kotzias demanding Monday the withdrawal of Turkey's "occupying troops".
Ankara responded bluntly: "Our position on this issue will not change."
Turkey maintains more than 35,000 troops there, and any prospects of reunification largely hinge on a drastic reduction of Ankara's military presence.
Several previous peace drives have stumbled over the issue, with Greek Cypriots demanding a total withdrawal of what they say is an occupying force and minority Turkish-speakers fearful of ethnic violence in the event of a pullout.
A diplomatic source told AFP before the talks began that Ankara was prepared to slash its troop numbers by as much as 80 percent, but Foreign Minister Mevlut Cavusoglu flatly denied that any such withdrawal was planned.