ANKARA (Reuters) - Any mistake in a planned U.S.-backed operation to drive Islamic State from the Iraqi city of Mosul could result in hundreds of thousands of refugees, Turkish presidential spokesman Ibrahim Kalin said on Thursday.
Turkey is locked in an escalating row with Iraq over who should take part in the Mosul assault and Kalin voiced concern that Kurdistan Workers Party (PKK) militants, viewed by Ankara and Western allies as terrorists, could be involved.
"Reports that the PKK may take part in the Mosul operation greatly worry us," he told a news conference, saying Turkey had no "secret agenda" in Iraq and favoured solving problems with Baghdad through dialogue.
The PKK has fought a 32-year insurgency in Turkey, in which more than 40,000 people have been killed, and its leadership is based in the mountains of northern Iraq.
Mosul, home to up to 1.5 million people, has been at the heart of Islamic State's self-declared caliphate in Iraq since 2014. The battle for the city is seen beginning this month.
"A mistake made there could result in hundreds of thousands of people becoming refugees," Kalin said. "A mistake in the Mosul operation will not be limited to Iraq, it will impact the whole region."
Turkish soldiers have been training Sunni Muslim and allied Kurdish Peshmerga units at Iraq's Bashiqa camp, near Mosul, and want them involved in the assault.
But Baghdad's Shi'ite-led government objects to the Turkish military presence and wants its own forces at the forefront. Turkey fears the use of Shi'ite militias, which Iraqi army units have relied on in the past, will stoke sectarian unrest.
"It is better for Iraq if the national army liberates Mosul and distances sectarian militias from the battle," Saudi Foreign Minister Adel al-Jubeir told reporters in Riyadh after a meeting with his Turkish and Gulf counterparts.
A joint statement after the meeting between Turkey and the six-nation Gulf Cooperation Council (GCC) raised concern about "plans to involve militia forces which perpetrated revenge attacks, mass killings, torture and clear human rights abuses against local populations" in the Mosul operation.
The Baghdad government has condemned the continued Turkish military presence at the Bashiqa camp and Prime Minister Haider al-Abadi has warned Turkey risked triggering a regional war.
Turkey, part of the U.S.-led coalition against Islamic State, says its troops are there as part of an international mission to train Iraqi forces to fight jihadists.
The United States has said any foreign forces in Iraq should have the approval of the Baghdad government.
Additional reporting by Tuvan Gumrukcu in Ankara, Nael Shyoukhi in Riyadh; Writing by Ece Toksabay and Daren Butler; Editing by Nick Tattersall and Ralph Boulton