astana russia turkey iran close finalize agreement create four de-escalation zone syria senior russian negotiator say thursday three side discuss detail agreement meet astana capital kazakhstan alexander lavrentyev lead russian delegation tell reporters main task international meet syria finalize establish four de-escalation zone lavrentyev say close reach agreement create four zone meet also involve representatives damascus government rebel factions continue friday lavrentyev say agreement likely include provision deployment monitor military police servicemen four zone specifically border previous round syrian peace talk astana july end agreement turkey raise objections russia iran back syrian president bashar al-assad government turkey support rebel hold talk kazakhstan since january meet week sixth russia say close syria deal turkey iran