istanbul russian-sponsored syrian peace congress schedule nov. 18 postpone main syrian kurdish group invite hold late objections turkey president tayyip erdogan spokesman say sunday ask comment russia foreign ministry spokeswoman refer regular weekly brief thursday say moscow work date venue participants lineup list expect participants include kurds since delete ministry website head kurdish pyd party indicate last week favor attend peace congress would first time kurds participate major diplomatic push end war syria russia tell us meet postpone pyd invite erdogan spokesman ibrahim kalin tell broadcaster ntv interview pyd emerge one powerful players syria since war begin 2011 say invite meet russian black sea city sochi turkey view pyd arm ypd affiliate offshoots kurdistan workers party pkk fight decades-long insurgency turkey designate terrorist group ankara unite state european union ypg control swathe northern syria kurdish-led local administrations set ally unite state core syrian defence force sdf drive islamic state militants much northern syria main rebel group fight overthrow syrian president bashar al-assad plan boycott peace congress sochi moscow say focus new constitution russia-backed syrian congress postpone turkish presidential spokesman