More than 92 per cent of Kurdish voters chose independence from Baghdad’s central government, Kurdish election monitors said on Wednesday.
Hendrin Mohammed, head of the Iraqi Kurdish region's election commission, announced the official results at a press conference, saying the referendum passed with 92.73 per cent support and a turnout of more than 72 per cent.
The vote was held across the autonomous Kurdish region's three provinces, Erbil, Dohuk and Sulaymaniyah, as well as in some disputed territories controlled by Kurdish forces but claimed by Baghdad, including Kirkuk.
Mr Mohammed said the "counting of votes was complete and that results would be considered final once they are certified by the Kurdish region's department of justice".
The non-binding referendum is unlikely to lead to formal independence, but it has escalated long-running tensions with Baghdad.
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Mr Mohammed's announcement came shortly after the Iraqi parliament called on prime minister Haider Al Abadi to send troops to the Kurdish-controlled city of Kirkuk to seize control of its oilfields.
The oil-rich and ethnically-diverse city fell under the control of Kurdish forces in 2014 following the chaos that ensued when ISIL extremists captured large swathes of the country, including Mosul.
A parliamentary resolution called on Mr Al Abadi to issue “orders for the security forces to be deployed in disputed areas."
“The government must bring back the oilfields of Kirkuk which are controlled by the ministry of oil,” the parliamentary resolution said.
Mr Al Abadi meanwhile called for the results of the Kurdish referendum on independence to be annulled as a condition for dialogue to resolve the escalating crisis.
In a speech to parliament, the prime minister renewed his ultimatum for the Kurdish region to hand over control of its international airports by Friday or face a ban on direct international flights.
The Kurdish region had earlier rejected the order from Baghdad to surrender control of its international airports to the central government, describing the demand as "illegal".
Angered by Monday's referendum on Kurdish independence, Mr Al Abadi warned on Tuesday that the Kurdistan Regional Government (KRG) had three days to "surrender" all land and air border crossings or face a shutdown of international flights.
He said humanitarian and other “urgent” flights would be exempt from the ban, however.
The Iraqi civil aviation authority has sent a notice to foreign airlines companies telling them that international flights to both Erbil, the capital of the Kurdish region, and Sulaymaniyah will be suspended at 3pm GMT on Friday and only domestic flights allowed.
But KRG transport minister Mowlud Murad told a news conference in Erbil on Wednesday that keeping control of the airports was necessary for the Kurds' fight against ISIL.
It came as airlines from Turkey, Lebanon and Egypt said they would suspend operations to and from Iraq's Kurdish region on Friday.
Turkish carriers Turkish Airlines, Atlas and Pegasus, which offer frequent connections for Iraqi Kurdistan, will halt their flights, the Turkish consulate in Erbil said.
EgyptAir, meanwhile, said it would stop flights to and from the Iraqi Kurdish capital "until further notice", as Lebanon's Middle East Airlines (MEA) said it would also stop flights.
"For now, we're stopping. The last flight is on the 29th, until they solve the issue," MEA chairman Mohammad Al Hout said, citing the notice from Iraq's civil aviation authority.
Mr Al Abadi on Tuesday said his government had decided to demand control of the airports because Monday's referendum had “destabilised” the region.
Referring to the Kurdish leadership, Mr Al Abadi added that “unfortunately, some have tried to weaken Iraq and be stronger than the state”.
“We are partners in this country, and the partnership means we work together and don’t carry out unilateral decisions that lead to division and conflict and weakness."
In another demand, he said all "oil revenues in Iraqi Kurdistan must also be returned to the control of the federal authorities".
The KRG held Monday's independence referendum despite mounting international calls for it to be postponed.
Iraqi officials have refused to negotiate with the Kurdish authorities and called the referendum "unconstitutional".
Also on Wednesday, Iraqi forces battled ISIL extremists near the city of Ramadi, west of Baghdad, after the militants infiltrated government lines.
Ramadi is the capital of vast, mainly Sunni Arab Anbar province, which has long been a bastion of insurgency and was retaken by the army from ISIL only in December 2015.