Iraq's Kurds faced mounting international pressure on Friday, including from neighbouring Iran, to call off an independence referendum that the UN Security Council warned was potentially destabilising.

It came ahead of a press conference on Saturday at which Iraqi Kurdish leader Massud Barzani is expected to announce whether the vote will go ahead as planned on Monday in the autonomous region.

The commander of the Iranian Revolutionary Guards' foreign operations, Major General Qassem Soleimani, was in Iraqi Kurdistan's province of Sulaimaniyah on Friday and was to head to its capital Arbil, a high-ranking source in the province said.

“It's his last visit before the referendum to advise Kurdish officials that Iran is seriously hostile to it and warn them to call it off,” the source said.

Iran has a sizeable Kurdish population and fears the vote will stoke separatist aspirations at home.

The Iraqi government is also opposed to the referendum in the oil-rich region, which it has called unconstitutional.

In 2014, after a dispute over oil exports, Baghdad decided to suspend payments to the Kurdish regional government of 17 per cent of Iraq's national budget.

Wages, including those of Kurdish peshmerga fighters, were slashed after the end of those transfers, which were worth around $12 billion and made up 80pc of the region's budget revenues.

“The Iranians are still pushing for negotiations between Kurdistan and Baghdad,” the source said.

Soleimani has told Kurdish officials that “Iran is pressuring Baghdad so it accepts Kurdish demands and solves the issues of the budget, peshmerga salaries and disputed areas”.

'Potentially destabilising'

Iraqi Kurdistan has since 2003 been made up of the three provinces of Arbil, Dohuk and Sulaimaniyah, but its leaders have laid claim to other areas that are constitutionally under Baghdad's authority, including the oil-rich province of Kirkuk.

The Iraqi Kurds would like these disputed areas to take part in the vote.

Neighbouring Turkey, which has its own Kurdish community, and Western nations including the United States are also against the vote.

On Thursday, the UN Security Council warned the referendum was “potentially destabilising”.

The council urged “dialogue and compromise” to address differences between the Iraqi government and the regional authorities.

It also said the vote could weaken the military campaign against the Islamic State jihadist group, “in which Kurdish forces have played a critical role”.

Baghdad this week started offensives to oust IS from the last two pockets it controls in Iraq.

Despite tensions over the referendum, Iraqi forces on Friday penetrated the northern IS-held town of Sharqat on their drive to retake the town of Hawija back from the jihadists.

Iraqi Prime Minister Haider al-Abadi said on Tuesday he rejected an independence referendum under any form, even non-binding.

He said the poll was “rejected, whether today or in the future, in the Kurdistan region within the 2003 borders or in the disputed areas”.

Iraqi president initiative

On Wednesday, Saudi Arabia urged Barzani to cancel the referendum to avoid further “crises” in the region.

But the Iraqi Kurdish leader has refused to give in, and on Thursday rejected an initiative from Iraqi President Fuad Massum ─ a Kurd ─ for negotiations.

Massum, in a document seen by AFP, suggested starting UN-backed talks towards a deal with Baghdad.

He suggested forming a high committee, to be presided over by the head of state and to include the parliament speaker as well as the prime ministers of Iraq and Iraqi Kurdistan.

The UN envoy for Iraq would also be involved.

In areas disputed between Arbil and Baghdad, some have issued strong warnings against the vote. In the town of Tuz Khurmatu in the province of Salaheddine, an official from the Hashed al-Shaabi paramilitary umbrella group has said he will not allow the poll.

“We're ready for a fight to the death,” said Atef Annajar, whose group is dominated by Iran-backed Shia militias, adding however that “the leadership is trying to calm the situation”.

Hadi al-Ameri, head of the powerful Iran-backed Badr organisation, last week vowed to defend the unity of Iraq, warning that the poll could trigger partition and civil war.

On September 16, a car bomb killed three people in disputed Kirkuk.