Defense Secretary Ash Carter, arriving in Turkey Friday, said he will tell Turkish leaders that it's important to respect Iraqi sovereignty. But he stopped short of saying that he will press the Turks to remove any forces that are operating in Iraq without Baghdad's invitation.

Carter's expected meetings in Ankara with top leaders and defense officials come amid escalating tensions between Turkey and Iraq, over Turkish military operations in northern Iraq as allied forces move to retake Mosul from Islamic State militants.

"We've long had discussions with everyone about this - about respect for Iraqi sovereignty in the course of the conduct of the counter-ISIL campaign," Carter told reporters traveling with him to Turkey. "It's very important for all the members of the counter-ISIL campaign to participate in that integrated way. Will I be talking with the Turks about that? Absolutely."

It was not clear how strong Carter intended to be in his discussions with Turkish leaders, or what impact it could have on the situation.

The key is to "keep everybody focused on the object here which is to defeat ISIL," Carter said, using another acronym for the Islamic State, "because that is a threat to all three of us."

The angry rhetoric between Iraq and Turkey has grown as the Mosul campaign continues to take shape.

Iraqi Prime Minister Haider al-Abadi and Turkish President Recep Tayyip Erdogan have traded insults, and earlier this week thousands of followers of a Shiite cleric rallied outside the Turkish Embassy in Baghdad, calling for an end to the Turkish "occupation."

They were referring to the presence of some 500 Turkish troops at a base north of Mosul who have been training Sunni and Kurdish fighters since last December. Baghdad says the troops are there without permission and has called on them to withdraw. Ankara has refused, and insists it will play a role in liberating the city.

The Turkish troops are training Kurdish forces loyal to Kurdish leader Masoud Barzani.

At the same time, the U.S. is also looking into reports that Turkish jets and artillery struck Syrian Kurds in northern Syria on Thursday, killing as many as 200.

Carter also said he has few details on the incident, and questions remain about the casualty total and whether or not the Kurdish forces were ones backed by the U.S.

The Syrian Kurdish forces have been a source of tension between NATO allies Turkey and the United States. The U.S. considers the militia group — the People's Protection Units or YPG — to be the most effective force in the fight against the Islamic State group in Syria. Turkey says it's an extension of its own outlawed Kurdish militants who have carried out a series of deadly attacks in Turkey in the past and considers it to be a terrorist organization.

Carter said he also wants to talk to Turkish leaders about the ongoing effort to secure Turkey's border with Syria. Turkey has stepped up its military air and ground operations against the Islamic State group in Syria, and recently was able to help retake the symbolically important town of Dabiq from the Islamic State group.

That, said Carter, was a "very significant victory."