The Iraqi government will not hold talks with the Kurdistan Regional Government (KRG) about the results of Monday's "unconstitutional" referendum on independence in northern Iraq, Iraqi Prime Minister Haider al-Abadi said.

"We are not ready to discuss or have a dialogue about the results of the referendum because it is unconstitutional," Abadi said in a speech broadcast on state TV on Monday night.

"Most of the problems of the [Kurdish] region are internal ones, not with Baghdad, and will be increased with the calls for separation," Abadi said, adding: "The economic and financial problems the region is suffering from are the result of corruption and mis-administration," the prime minister said.

READ MORE: Iraqi Kurds count referendum votes

Masoud Barzani, the leader of the KRG, said the referendum is not binding and was meant to be a legitimate mandate to negotiate with Baghdad and neighbouring countries over the secession of the Kurdish-controlled region from Iraq.

Erbil-based Rudaw TV, citing the Independent High Elections and Referendum Commission, said 78 percent of the more than five million eligible voters turned out to vote.

In Kirkuk, authorities declared a curfew an hour and a half before polls closed as jubilant Kurds started to celebrate.

The vote was expected to deliver a comfortable "yes", and final results should be announced in 72 hours.

'Unilaterally declared'

UN Secretary-General Antonio Guterres expressed regret that the Kurds have gone ahead with the referendum.

UN spokesman Stephane Dujarric said Guterres noted the referendum was "unilaterally declared, included disputed areas" and was opposed by Iraqi authorities and the global community.

The spokesman said Guterres regretted that opportunities for negotiations were not seized and viewed the decision to hold the vote as potentially destabilising.

The vote held Monday was billed by the Kurdish leadership as an exercise in self-determination. To Baghdad, the vote threatens a redrawing of Iraq's borders, while leaders in Turkey and Iran fear the move would embolden their own Kurdish populations.

READ MORE: Iraqi Kurdistan - Playing the independence game

Turkey's military confirmed that Turkey and Iraq will conduct joint military drills in Turkey along an area bordering Iraq's semi-autonomous Kurdish region.

A military statement on Monday announced a new "phase" in the military exercises that were launched last week in a clear warning to Iraqi Kurds, saying units from Iraq's armed forces would arrive in Turkey later in the evening to join Turkish troops.

The joint drills are set to kick off on Tuesday, the military said, without providing details.

The Turkish military also published photographs of Iraqi troops, including one showing them holding the flags of Turkey and Iraq and posing in front of an Iraqi Air Force plane.