ISTANBUL (AP) — The rival leaders of ethnically split Cyprus said Wednesday they would meet with U.N. Secretary-General Ban Ki-moon later this month to take stock of ongoing reunification talks and ask him to step up his personal involvement in the months ahead. Cyprus President Nicos Anastasiades, a Greek Cypriot, and the breakaway Turkish Cypriot leader Mustafa Akinci, said that much progress has been achieved in 16 months of talks, but key differences remain. The leaders "will exchange views with (Ban) and will request him to intensify his personal engagement in the process in the months to come," the statement said following the end of an intensified, eight-meeting phase of talks held at the disused Nicosia airport inside a U.N.-controlled buffer zone.