Iraq's Kurds will hold an independence referendum next month despite a US request to postpone it, a high-ranking Kurdish official said on Saturday.
The United States and other western nations are worried that the vote could ignite a fresh conflict with Baghdad and turn into another regional flashpoint. Turkey, Iran and Syria, which together with Iraq have sizeable Kurdish populations, all oppose an independent Kurdistan.
"The date is standing, September 25, no change," said Hoshyar Zebari, a close adviser to president Masoud Barzani of the Kurdistan Regional Government.
The US secretary of state Rex Tillerson asked Mr Barzani to postpone the referendum during a phone call on on Thursday, Mr Zebari said.
The Kurdish presidency statement issued on Friday said "the people of the Kurdistan Region would expect guarantees and alternatives for their future" in case the referendum was postponed.
The US state department said in June that it was concerned that the referendum would distract from "more urgent priorities" such as the defeat of ISIL.
The extremist group's self-proclaimed "caliphate" effectively collapsed last month when US-backed Iraqi forces completed the takeover of Mosul, its main city in Iraq, after a nine-month campaign in which Kurdish Peshmerga fighters took part. However, the militants still control territory in western Iraq and eastern Syria.
The United States has pledged to maintain its backing to allied forces in both countries until ISIL's total defeat.
The Kurds have been seeking an independent state since at least the end of the First World War, when colonial powers divided up the Middle East, but their territory ended up split between modern-day Turkey, Iran, Iraq and Syria.
Mr Barzani, whose father led struggles against Baghdad in the 1960s and 1970s, said in July that the Kurds would take responsibility for the expected "yes" outcome of the referendum, and pursue its implementation through dialogue with Baghdad and regional powers to avoid conflict.
"We have to rectify the history of mistreatment of our people and those who are saying that independence is not good, our question to them is: 'if it's not good for us, why is it good for you?'," he said in an interview in the KRG capital, Erbil.
Iraq has been led by Shiites since the overthrow of Saddam Hussein, a Sunni, by the US-led invasion of 2003.
The country's majority Shiite community mainly lives in the south while the Kurds and Sunni Arabs inhabit two corners of the north. The centre around Baghdad is mixed.
Kurdish officials have said disputed areas, including the oil-rich Kirkuk region, will be covered by the referendum, to determine whether they would want to remain in Kurdistan.
The Peshmerga in 2014 prevented ISIL from capturing Kirkuk, in northern Iraq, after the Iraqi army fled in the face of the militants. They are effectively running the region, which is also claimed by Turkmen and Arabs.
Iran-backed Iraqi Shiite militias have threatened to expel the Kurds by force from this region and three other disputed areas — Sinjar, Makhmour and Khanaqin.