baghdad iraq prime minister insist thursday kurdish independence referendum declare void apparent rejection kurdistan region offer freeze independence push part efforts resolve crisis talk accept anything cancellation respect constitution haider al-abadi say statement kurdistan regional government krg propose wednesday immediate ceasefire suspension referendum result start open dialogue federal government base iraqi constitution baghdad always consider kurdish secession referendum illegal respond last week seize back city kirkuk oil-producing areas around territory kurds capture militant group islamic state abadi order army recapture dispute territory demand central control iraq border cross turkey fish-khabur locate inside kurdish autonomous region fish-khabur strategically vital oil kurdish government-held part northern iraq cross via pipeline turkey main route area export crucial kurdish independence bid fight central government kurds particularly tricky unite state close ally side arm train kurds central government army fight islamic state iraqi pm abadi insist outcome kurdish independence referendum cancel