Iraqi Prime Minister Haider al-Abadi on Tuesday said he understood the Kurdish minority's statehood aspirations but bemoaned its leadership's decision to hold an independence referendum in September.

"Every part of Iraq has aspirations and has a dream, and we respect that, even if we disagree with it," he said, responding to the Kurdish push to achieve statehood.

"We live in one homeland and they are our partners," Abadi said, referring to the Kurds.

"We have a constitution that we've voted on, we have a federal parliament and a federal government," he said. "The referendum at this time is not opportune."

Abadi was speaking at a press conference in Baghdad nearly a week after the presidency of Iraq's autonomous Kurdish region announced a referendum on independence for September 25.

The Kurds had already said they would aim to organise such a vote after the battle of Mosul against the Islamic State group, which appears to be in its final stages, was won.

Such a referendum, the positive outcome of which is in little doubt, would be non-binding and leave the approximately five million Kurds of northern Iraq some way away from actual independence.

The support of the federal Iraqi government, of key neighbours such as Iran and Turkey and of major players such as the United States is seen as essential to achieving a viable separation.

Baghdad's reaction to the announcement was seen internally as relatively meek given that the break-up of the country is at stake.

An Iraqi official told AFP on condition of anonymity that an overly antagonistic reaction to the announcement of the referendum would serve only to unite Kurdish factions against Baghdad and give the independence drive more momentum.

Internal division is one of the Kurds' main weaknesses as they set the wheels in motion for an independence process that is likely to last years.

Washington and other Western partners of the Kurdish administration have taken much the same line as Baghdad, recognising their legitimate independence aspirations but warning that the timing of the referendum was not helpful.