US Defence Secretary Ashton Carter said Friday he was confident that Turkey would take part in the operation to retake the Iraqi city of Mosul from the Islamic State group.
"I think there is agreement there in principle," he said after a visit to Turkey, following tensions between Ankara and Baghdad that have alarmed Washington.
"Iraq understands that Turkey as a member of the counter-ISIL (IS) coalition will play a role in counter-ISIL operations in Iraq and secondly that Turkey since it neighbours the region of Mosul has an interest (in) the ultimate outcome in Mosul," Carter said.
"I am confident that we can work things out and there are things that would be productive for Turkey to do and we just need to work through these practicalities."
A senior US defence official indicated that Turkey could provide medical or humanitarian support, or train Iraqi forces.
Earlier on Friday, Carter met with President Recep Tayyip Erdogan and other top officials during his short visit to Turkey, a crucial ally in the fight against IS.
Baghdad has called for the withdrawal of hundreds of Turkish troops from Bashiqa near Mosul where they have been deployed to train Iraqi fighters for the battle for the jihadist stronghold.
Ankara fears that the operation to retake Mosul could be spearheaded by Shiite militia and also include Kurdish militia vehemently opposed by Turkey.
Carter also saw a military and political role for Turkey in an eventual assault on the Syrian city of Raqa where IS has established its de facto capital.
"Likewise, Turkey will have a role ultimately in the collapse of Raqa and then as a party in the region will have an interest in making sure that the governance of Raqa is one that is reflective of the population there," he said.
"We want to get ISIL out of Raqa, we want to do that as soon as possible and we want the victory to last."