unite nations syria foreign minister say saturday victory within reach country damascus hop de-escalation zone help reach cessation hostilities liberation aleppo palmyra lift siege deir ezzor eradication terrorism many part syria prove victory within reach foreign minister walid al-moualem say speech unite nations general assembly russia turkey iran negotiate separately months kazakh capital astana try reduce violence grind create de-escalation zone across country although talk cover long-term political solution six-year civil war moualem praise constructive role russia iran back syrian president bashar al-assad say syria encourage de-escalation zone hop would lead actual cessation hostilities nevertheless say syria reserve right respond violation party syria also stress zone temporary arrangement must violate territorial unity syria early month russia iran turkey agree deploy observers edge de-escalation zone syria idlib province largely control islamist insurgents move fall broad deal would set four zone across syria de-escalation plan ease fight part western syria rebel factions government force loyal assad assad gain military upper hand array rebel group include receive back unite state turkey gulf monarchies critics describe de-escalation plan de facto partition syria years multi-sided conflict moscow tehran ankara deny say zone temporary although could extend beyond initial six-month term syria 's moualem say victory within reach de-escalation zone temporary