Turkey and Iran presented a united front in their opposition to Iraqi Kurdish aspirations of independence, during a visit Wednesday by Turkish President Recep Tayyip Erdogan that signals a warming of ties.
"Some leaders of Iraq's Kurdistan region have made erroneous decisions which must be corrected," Iran's President Hassan Rouhani said after talks with Erdogan, visiting Tehran for the first time since 2015.
"Iran, Turkey and Iraq are obliged to take serious and necessary measures," he said in reference to retaliatory measures adopted since Iraqi Kurdistan's disputed September 25 independence referendum.
Erdogan, in a translation on Iranian state television of his comments, warned of "stronger" measures to follow and said the autonomous Kurdish region in northern Iraq would remain "isolated".
Iran's supreme leader Ayatollah Ali Khamenei, who also met with Erdogan, said "the referendum in Iraqi Kurdistan was a betrayal".
Iran and Turkey needed to "take serious, political and economic (measures) together", he said in a statement after their meeting.
The two governments fear the secession of Iraq's Kurds would stoke separatist sentiment among their own large Kurdish minorities and are eager to work together with the federal government in Baghdad to block it.
Both Iran and Turkey have held military manoeuvres close to their borders with Iraqi Kurdistan to ratchet up the pressure on Kurdish leaders.
Those exercises have also involved forces of the federal government in Baghdad, which has demanded the annulment of the vote which returned a 92.7% "yes" for independence.
Baghdad imposed a ban on all international flights to Kurdish airports on Friday prompting an exodus of foreigners.
Iran has ordered a halt to all trade in fuel products with Iraqi Kurdistan and has said it will allow Iraqi federal forces to deploy at its border crossings with the region.
Turkey has threatened to close its land border and halt the export of oil from Iraqi Kurdistan to the Turkish port of Ceyhan, an economic lifeline.
Since 1984, Turkey has battled rebels of the outlawed Kurdistan Workers' Party (PKK) which has rear bases in northern Iraq and which initially sought to create a breakaway state.
Two Kurdish rebel groups are active in Iran – the Kurdistan Democratic Party of Iran (KDPI) and the Party of Free Life in Kurdistan (PJAK).
Iran and Turkey have been rivals for centuries but have recently sought to forge a pragmatic relationship, with the Islamic republic strongly supporting Erdogan after last year's failed coup.