moscow russian president vladimir putin turkish president tayyip erdogan discuss upcoming meet astana process syrian conflict kazakh capital late october kremlin say saturday phone conversation putin erdogan talk joint efforts within astana process include creation de-escalation zone syria coordination towards resolve syria situation kremlin say statement astana talk broke russia turkey iran mid-september three countries agree post observers edge de-escalation zone northern syria idlib region largely control islamist militants putin erdogan also say agreements reach russia turkey ankara late september successfully implement particularly trade economic relations overall conversation business-like constructive direct strengthen bilateral cooperation interaction regional agenda kremlin say russian-turkish trade relationship affect dispute supply turkish tomatoes russia moscow yet fully restore dispute add risk russian grain trade turkey russia large market turkish tomato producers say week allow purchase 50,000 tonnes turkish tomatoes four turkish producers dec. 1. announcement come several days turkey second large buyer russian wheat say impose requirement additional approval russian agriculture supply turkish authorities kremlin say putin erdogan discuss syria phone call