Turkey has threatened to halt co-operation with Washington in Iraq after a US offensive in north Iraq and the reported deaths of ethnic Turkmen civilians.
US troops begun a major offensive last week in the town of Tal Afar, a suspected haven for foreign fighters near the Syrian border, which has a large indigenous Turkmen population.
Turkey, a Nato ally of the United States, views northern Iraq as part of its sphere of influence and has close ethnic and linguistic links with the region's Turkmen minority.
"If things continue in this way, we told them [the US side] very clearly that Turkey's co-operation on matters concerning Iraq will come to an end," CNN Turk television quoted Foreign Minister Abdullah Gul as saying.
He did not specify what co-operation might suffer, but Turkey is a key US ally in a largely hostile region and US forces, for example, use its Incirlik military base.
Earlier, the US ambassador to Turkey, Mr Eric Edelman, tried to calm Turkish concerns, saying the US forces were doing their best to keep civilian losses to a minimum as they fought the Iraqi insurgents.
Last Friday, Turkey's Foreign Ministry urged the United States to halt its offensive. The Turkish military also said it was monitoring the situation closely in Tal Afar.