Comments come as Iraqi president Fuad Masum called off his visit to New York on Sunday to work on resolving the dispute over the referendum.
Military intervention possible in Kurdish independence, Iraqi PM says
Iraq is prepared to intervene militarily if the Kurdish region's planned independence referendum results in violence, prime minister Haider Al Abadi said.
If the Iraqi population is "threatened by the use of force outside the law, then we will intervene militarily", Mr Al Abadi said.
The semi-autonomous Kurdish region plans to hold the referendum on independence from Iraq on September 25 in the three governorates that make up the region and in disputed areas controlled by Kurdish forces but which are claimed by Baghdad.
"If you challenge the constitution and if you challenge the borders of Iraq and the borders of the region, this is a public invitation to the countries in the region to violate Iraqi borders as well, which is a very dangerous escalation," Mr Al Abadi said.
The prime minister's comments on Saturday added to rising tensions after Kurdish leader Masoud Barzani threatened violence if the Iraqi military or government-backed militias attempted to move into disputed territories that are now under the control of Kurdish militias.
On Sunday, Iraqi president Fuad Masum cancelled his attendance at the UN General Assembly in New York to work on resolving the referendum dispute.
Mr Masum asked Mr Al Abadi to attend the UN meeting as he faces “a deep political crisis that could result in adverse impacts on the national interests if it is left unsolved”, his office said.
The leaders of Iraq's Kurdish region have said they hope the referendum will push Baghdad to come to the negotiating table and create a path to independence. However, Mr Al Abadi said the vote would complicate such negotiations.
"It will make it harder and more difficult," he said, but added: "I will never close the door to negotiations. Negotiations are always possible."
The oil-rich city of Kirkuk is likely to be a point of contention as forces, both Kurdish and Baghdad-backed, are experiencing a heightened state of tensions.
"It's chaotic there," said Muhammad Mahdi Al Bayati, a senior leader of Iraq's mostly Shiite fighters known as the Hashed Al Shaabi or Popular Mobilisation Forces.
Mr Al Bayati's Baghdad-sanctioned forces are deployed around Kirkuk as well as other disputed territories in Iraq's north, where he said "anything could be the spark that burns it all down."
Iraq's Kurds have come under increasing pressure to call off the vote from the US, which has backed them since an American enforced no-fly zone in the north following the Gulf War allowed the minority to establish a regional government in 1992.
The White House has called instead for the Kurdish region to start "serious and sustained dialogue with Baghdad".
"Holding the referendum in disputed areas is particularly provocative and destabilising," the White House warned.
Neighbouring countries are also weighing in against the vote, wary of how it might influence regional politics and with Kurdish populations of their own that also aspire to greater independence.
Turkish president Recep Tayyip Erdogan said he would discuss his concerns with Iraq's prime minister during his visit to the US.
"We will have a meeting with Mr Abadi in the United States, and from what we can see our goal is the same. Our goal is not dividing Iraq," Mr Erdogan said.
Turkey is home to the largest Kurdish population in the world, has been battling an insurgency by the Kurdistan Workers Party militants in the south-west of the country since the 1980s.
Iran also joined voiced opposition to the referendum saying independence could spark a situation that would "disrupt security".
Senior Iranian official Ali Akbar Velayati said Tehran was "the strategic ally of Iraq, and will agree to what the legitimate government of the country accepts".
Mr Al Abadi has said he is focused on legal responses to the referendum. Earlier this week parliament rejected the referendum in a vote boycotted by Kurdish MPs.
"If [Iraq's Kurds] want to go along that road, they should work toward amending the constitution," Mr Al Abadi told Associated Press on Saturday.
"In that case we have to go all the way through parliament and a referendum to the whole Iraqi people."