WASHINGTON — Defense Secretary Jim Mattis on Friday urged Iraqi and Kurdish Peshmerga forces to focus on defeating the Islamic State group and not fight each other, as tensions spiked in the disputed region around Kirkuk.

“Everybody stay focused on defeating ISIS,” Mattis said, using an alternate acronym for IS. “We can’t turn on each other right now. We don’t want this to go to a shooting situation.”

Speaking to reporters as he flew back to Washington from a three-day trip to Florida, Mattis said the U.S. is trying to calm the already fractious relations between the two sides and figure out a way ahead.

Kurdish forces had taken positions southwest of the oil-rich city of Kirkuk, but later withdrew. Iraqi government troops also have been moving around the area.

Tensions between the two sides have been escalating since the Kurds voted for independence from Iraq in a non-binding referendum last month. The Peshmerga took control of Kirkuk when Iraqi defenses crumbled in the face of the advancing Islamic State group in 2014. Baghdad is demanding the Kurds return the city, which falls outside the autonomous Kurdish zone, to federal authority.

The roiling conflict grew in recent days with the movement of forces on both sides, raising U.S. concerns that as the fight with IS begins to wind down, the long-simmering sectarian violence between Kurds, Sunnis and Shiites will once again erupt.

So far, Mattis said, there has been no actual fighting between the Iraqi troops and the Peshmerga around Kirkuk. He said U.S. forces that are embedded with the Iraqi and Kurdish units are working to “make certain they keep any potential for conflict off the table.”

He added, “We’re trying to tone everything down, and let’s figure out how we go forward without losing our sight on the enemy.”

He said U.S. leaders are working with both sides to find a diplomatic compromise.

“We’ve got to find a way to move forward,” Mattis said. “Geography is not going to change. They’re going to be alongside each other, no matter what.”

In comments to Pentagon reporters later Friday, Mattis said the U.S. has been watching for the problem. “Obviously, once ISIS is down and out we don’t want another terrorist group to rise up and also some of the old conditions or tensions now come back to the forefront.”

Also, he added: “We don’t want to take our eye off the ball with ISIS this close to being crushed. So, we are working, trying to be a contributor to solving this.”

Mattis was in southern Florida visiting several of his top military commanders, including Gen. Joseph Votel, head of U.S. Central Command, which oversees the Middle East, including the war in Iraq. He also met with Gen. Tony Thomas, head of U.S. Special Operations Command, and Adm. Kurt Tidd, head of U.S. Southern Command.


AP national security writer Robert Burns contributed to this report.