A U.N. envoy says everything is up for discussion in an intensified phase of ongoing talks aimed at reunifying ethnically divided Cyprus.

Espen Barth Eide says there are no remaining "taboo" issues that the rival leaders would opt to tackle at a later stage.

Eide said Wednesday it's the first time since he took over as peace talks facilitator two years ago that even the toughest issues, including military intervention rights Cyprus' existing constitution grants to Greece, Turkey and Britain, will be discussed.

Cyprus was split in 1974 when Turkey invaded after a coup aiming at union with Greece. Nicos Anastasiades, the Greek Cypriot president of Cyprus' internationally recognized government, and breakaway Turkish Cypriot leader Mustafa Akinci have been engaged in renewed talks since May 2015.