Although the referendum cannot legally cleave Iraq into two, the results can trigger more instability in an already volatile region. The Iraqi central government and other countries have emphasised that the use of force may come into play.
How has the vote affected Iraq and the wider region?
The results of the Kurdish Regional Government's referendum in support of an independent region in the northern Iraq could trigger further instability in the Middle East.
The poll has escalated tensions between the Kurds and Iraq's Arab majority, raising fears of unrest.
Iraq will not allow the Kurdish referendum to divide the country and will take necessary measures to ensure the stability of the country, Iraqi political analyst Wathiq al Hashimi said.
And even the vote is non-binding and will not automatically lead to cessation of the semi-autonomous Kurdish majority areas, it has sparked renewed tensions with Baghdad, Turkey and Iran.
Washington has also warned the vote would "increase instability".
But the vote is also seen by the Kurds as a major step towards a long-cherished dream of statehood in the region, where formal borders have remained in place for decades and recent conflicts have resulted in several de facto partitions.
TRT World's Nicole Johnston reports from Erbil, northern Iraq.
What was the outcome of Monday's vote?
The turnout was 72 percent, with 3.3 million of the 4.58 million registered voters taking part, election commission spokesman Shirwan Zirar said late Monday.
Prior to the vote, the commission had put the electorate at 5.3 million.
Results were expected within 24 hours, with an overwhelming "yes" vote predicted.
How have the KRG's neighbours reacted?
However, opposition from the international community, as well as Iraq and its neighbours, makes any immediate formal separation unlikely.
That kind of de facto partition, once rare in the Middle East, has become far more common in the chaos that followed the 2011 Arab uprising.
Iran and Turkey fear an administratively separate region will give terror groups a new stronghold - terror groups which both countries have struggled to contain.
With 30 million ethnic Kurds scattered across the region, mainly in Iraq, Iran, Turkey and Syria, Tehran and Ankara also fear the spread of separatism to their own Kurdish populations.
TRT World speaks to an Iraq analyst Ahmed Rushdi in Baghdad about the potential fallout.
How has Iraqi's government responded?
The Iraqi leadership will not hold talks with KRG about the results of the "unconstitutional" referendum held on Monday in northern Iraq, Iraqi Prime Minister Haider al Abadi said.
As voting progressed, Iraq's parliament ordered Abadi to "deploy forces" in disputed areas.
The Iraqi army started "major manoeuvres" with the Turkish army at the border, the Iraqi defence ministry said, outlining coordinated measures by the two countries against the KRG in retaliation for the referendum.
Asked about the risks of armed conflict, Abadi's spokesman Saad al Hadithi said, "If there are clashes in these zones, it will be the job of federal forces to apply the law."
Karim al Nuri, head of the Badr Brigade which forms part of the powerful Hashd al Shaabi paramilitary units, suggested the Shia group was ready to deploy to "Kirkuk and the disputed zones occupied by armed gangs, outlaws who do not respond to the army command."
Will the Assad regime negotiate with the KRG?
The Syrian regime is open to negotiations with Kurds over their demand for autonomy within Syria's borders, the foreign minister has said.
Walid al Moualem said the regime could discuss the Kurdish demand once Daesh is defeated, state news agency SANA reported, citing an interview with Russia Today.
Moualem reiterated the regime's rejection of that referendum, saying Damascus supported Iraqi unity, but he noted that Syria's Kurds "want a form of autonomy within the borders of the Syrian Arab Republic."
Which options are Turkey looking at?
A small group of soldiers holding aloft an Iraqi and a Turkish flag walked across the dusty plain where military exercises, launched last week, were being held some 4 kilometres (2.5 miles) from the Habur border gate, the witness said.
Turkish President Tayyip Erdogan said all options, from economic to air and land military measures, were on the table in response to the referendum.
In a speech made at the presidential palace on Tuesday, Erdogan said Turkey would not hesitate to use the means at its disposal if the road to peace is blocked. He hoped the KRG would come to its senses.
Erdogan accused Kurdish leader Masoud Barzani of “treachery” for pursuing the referendum and warned that the KRG will not able to find “food and clothes” when Turkey stops trading with them.
"Until the very last moment, we weren't expecting Barzani to make such a mistake as holding the referendum, apparently we were wrong," Erdogan said.
"This referendum decision, which has been taken without any consultation, is treachery."
Erdogan, whose comments were broadcast live on television, again threatened to cut off the pipeline that carries oil from northern Iraq to the outside world.
Which side have the UK chosen, if any?
British Foreign Secretary Boris Johnson reiterated London's opposition to the vote, urging "all sides to refrain from provocative statements and actions in its aftermath.
"The priority must remain the defeat of Daesh and returning stability to liberated areas," he added, a reference to Daesh who continue to control parts of Iraq and Syria, including a pocket west of Kirkuk.
Are the UN supporting the vote?
In New York, UN chief Antonio Guterres also expressed concern about the "potentially destabilising effects" of the referendum.
Expressing respect for "the sovereignty, territorial integrity and unity of Iraq," he called for differences to be resolved through "structured dialogue and constructive compromise".
What was the US response?
The US Department of State said in a statement it was “deeply disappointed” the KRG decided to conduct the referendum but added that the United States’ “historic relationship” with the people of the Kurdish region of northern Iraq would not change.